Copyright Notice
[0001] This patent document contains material subject to copyright protection. The copyright
owner has no objection to the reproduction of this patent document or any related
materials in the files of the Patent Office, but otherwise reserves all copyright
whatsoever.
Field of Invention
[0002] The present invention relates to a method and apparatus for selecting a description
or part of a description of a resource. The invention also relates to an apparatus
and a computer program product for implementing the method.
Background
[0003] As network connectivity has continued its explosive growth and digital storage has
become smaller, faster, and less expensive, the quantity of electronically-accessible
resources has increased enormously. So much so that the discovery and location of
the available resources has become a critical problem. These electronically-accessible
resources can be digital content (e.g., digital images, video and audio) which may
be available over the network, web-based resources (e.g., HTML/XML documents) and
electronic devices (e.g., printers, displays. etc.). In addition, there are electronically-accessible
catalogues of other resources, which may not be electronically accessible (e.g., books,
analog film media, etc.). What is needed is a consistent method of describing resources
so that location of resources, electronically-accessible or otherwise, can be more
readily achieved.
[0004] The problems of consistent resource description are twofold. First, there is the
problem of acceptance of a standard (consistent) method of resource description. The
second problem is related to the generation of descriptions. Often the cost of this
process is significant.
[0005] The ready adoption of HTML browsers for the purposes for browsing and locating textual
information indicates that humans like to browse for information. Currently, however
no form of generic browsing of non-textual electronically-accessible resources exists.
For example, browsing of a library of text documents is typically enabled using an
HTML browser by providing a table of contents and then linking the relevant HTML (textual)
documents to anchors in an HTML document. Currently, there is no general way of browsing
through a library containing, for example, digital video resources. For such browsing
to be enabled it is necessary to have a consistent way of describing resources in
much the same way that HTML provides a consistent way of representing textual information.
[0006] If a consistent method of describing resources can be achieved then consistent methods
of selecting resource descriptions from formulated queries can be contemplated.
[0007] Furthermore, it is also possible to develop methods and build devices that facilitate
resource discovery, understanding and presentation. Resources can be composite items
involving other resources and can include schedules for presentation, delivery and/or
consumption. Video presentations can therefore be viewed as just another electronically-accessible
resource and as such can be described in a similar way to items of digital content
(like images) video and audio). The description of the video presentation effectively
provides an efficient encoding for the presentation.
Summary of the Invention
[0008] It is a concern of the present invention to ameliorate one or more disadvantages
of the prior art.
[0009] According to one aspect of the invention, there is provided a method of utlising
electronically-accessible resources using descriptions of said resources, wherein
said descriptions of said resources have descriptor components, said descriptor components
having attributes representative of at least two axes of access to the resources and
wherein said descriptions have links to corresponding said electronically- accessible
resources, said method comprising the steps of: reading said descriptions; displaying
items, wherein each item is associated with a corresponding said descriptor component
of a said read description that has at least one said attribute; and browsing said
descriptions of the resources and their corresponding electronically-accessible resources
via said links using said displayed items.
[0010] According to another aspect of the invention, there is provided a method of utilising
electronically-accessible resources using descriptions of said resources, wherein
said descriptions of said resources have descriptor components, said descriptor components
having attributes representative of at least two axes of access to the resources and
wherein said descriptions have links to corresponding said electronically- accessible
resources, said method comprising the steps of: reading said descriptions; displaying
items, wherein each item is associated with a corresponding said descriptor component
of a said read description that has at least one said attribute; specifying a query
in terms of index descriptors; searching said descriptions of the resources using
said query; and locating said corresponding electronically-accessible resources using
said links associated with said displayed items.
[0011] According to still another aspect of the invention, there is provided a method of
utilising electronically-accessible resources using descriptions of said resources,
wherein the descriptions of said resources have descriptor components, each said descriptor
component comprises the association of a feature of a said resource with a representative
value for that feature, and one or more of said descriptor components including a
table of contents attribute and one or more of said descriptor components including
an index attribute, and wherein said descriptions have links to corresponding said
electronically-accessible resources, said method comprising the steps of: reading
said descriptions; displaying a table of contents containing table of contents items,
wherein each table of contents item is associated with a corresponding said descriptor
component that has a table of contents attribute; selecting one said displayed table
of contents item; displaying an index containing index items, wherein each said displayed
index item is associated with a corresponding said descriptor component that has an
index attribute and that is associated with the said selected table of contents item;
selecting one or more index items in the displayed index; specifying a said representative
value or values for the one or more said selected index items; searching said descriptions
of the resources for said one or more selected index items and their corresponding
said specified representative value or values; and locating one or more said descriptions
of the resources corresponding to said one or more selected index items and their
corresponding said specified representative value or values.
[0012] According to still another aspect of the invention, there is provided a method of
utilsing an electronically-accessible resource using a description of said resource,
wherein the description of said resource has descriptor components, each said descriptor
component comprises the association of a feature of said resource with a representative
value for that feature, and one or more of said descriptor components including a
table of contents attribute and one or more of said descriptor components including
an index attribute, said method comprising the steps of: reading said descriptions;
displaying a table of contents containing table of contents items, wherein each table
of contents item is associated with a corresponding said descriptor component that
has a table of contents attribute; selecting one said displayed table of contents
item for the annotation; displaying an index containing index items, wherein each
said displayed index item is associated with a corresponding said descriptor component
that has an index attribute and that is associated with the said selected table of
contents item; selecting one said displayed index item; associating said selected
displayed index item with said selected table of contents item; choosing a said representative
value for the selected index item; and associating said chosen representative value
with said feature which corresponds to said selected index item, wherein said chosen
representative value and its corresponding feature provide an annotation of the resource.
[0013] According to still another aspect of the invention, there is provided apparatus for
utilising electronically-accessible resources using descriptions of said resources,
wherein said descriptions of said resources have descriptor components, said descriptor
components having attributes representative of at least two axes of access to the
resources and wherein said descriptions have links to corresponding said electronically-
accessible resources, said apparatus comprising: means for reading said descriptions;
means for displaying items, wherein each item is associated with a corresponding said
descriptor component of a said read description that has at least one said attribute;
and means for browsing said descriptions of the resources and their corresponding
electronically-accessible resources via said links using said displayed items.
[0014] According to still another aspect of the invention, there is provided apparatus for
utilising electronically-accessible resources using descriptions of said resources,
wherein said descriptions of said resources have descriptor components, said descriptor
components having attributes representative of at least two axes of access to the
resources and wherein said descriptions have links to corresponding said electronically-
accessible resources, said apparatus comprising: means for reading said descriptions;
means for displaying items, wherein each item is associated with a corresponding said
descriptor component of a said read description that has at least one said attribute;
means for specifying a query in terms of index descriptors; means for searching said
descriptions of the resources using said query; and means for locating said corresponding
electronically-accessible resources using said links associated with said displayed
items.
[0015] According to still another aspect of the invention, there is provided apparatus for
utilising electronically-accessible resources using descriptions of said resources,
wherein the descriptions of said resources have descriptor components, each said descriptor
component comprises the association of a feature of a said resource with a representative
value for that feature, and one or more of said descriptor components including a
table of contents attribute and one or more of said descriptor components including
an index attribute, and wherein said descriptions have links to corresponding said
electronically-accessible resources, said apparatus comprising: means for reading
said descriptions; means for displaying a table of contents containing table of contents
items, wherein each table of contents item is associated with a corresponding said
descriptor component that has a table of contents attribute; means for selecting one
said displayed table of contents item; means for displaying an index containing index
items, wherein each said displayed index item is associated with a corresponding said
descriptor component that has an index attribute and that is associated with the said
selected table of contents item; means for selecting one or more index items in the
displayed index; means for specifying a said representative value or values for the
one or more said selected index items; means for searching said descriptions of the
resources for said one or more selected index items and their corresponding said specified
representative value or values; and means for locating one or more said descriptions
of the resources corresponding to said one or more selected index items and their
corresponding said specified representative value or values.
[0016] According to still another aspect of the invention, there is provided apparatus for
utilising an electronically-accessible resource using a description of said resource,
wherein the description of said resource has descriptor components, each said descriptor
component comprises the association of a feature of said resource with a representative
value for that feature, and one or more of said descriptor components including a
table of contents attribute and one or more of said descriptor components including
an index attribute, said apparatus comprising: means for reading said descriptions;
means for displaying a table of contents containing table of contents items, wherein
each table of contents item is associated with a corresponding said descriptor component
that has a table of contents attribute; means for selecting one said displayed table
of contents item for the annotation; means for displaying an index containing index
items, wherein each said displayed index item is associated with a corresponding said
descriptor component that has an index attribute and that is associated with the said
selected table of contents item;means for selecting one said displayed index item;
means for associating said selected displayed index item with said selected table
of contents item; means for choosing a said representative value for the selected
index item; and means for associating said chosen representative value with said feature
which corresponds to said selected index item, wherein said chosen representative
value and its corresponding feature provide an annotation of the resource.
[0017] According to still another aspect of the invention, there is provided a computer
readable medium comprising a computer program for utilising electronically-accessible
resources using descriptions of said resources, wherein said descriptions of said
resources have descriptor components, said descriptor components having attributes
representative of at least two axes of access to the resources and wherein said descriptions
have links to corresponding said electronically- accessible resources, said computer
program comprising: code for reading said descriptions; code for displaying items,
wherein each item is associated with a corresponding said descriptor component of
a said read description that has at least one said attribute; and code for browsing
said descriptions of the resources and their corresponding electronically-accessible
resources via said links using said displayed items.
[0018] According to still another aspect of the invention, there is provided a computer
readable medium comprising a computer program for utilising electronically-accessible
resources using descriptions of said resources, wherein said descriptions of said
resources have descriptor components, said descriptor components having attributes
representative of at least two axes of access to the resources and wherein said descriptions
have links to corresponding said electronically- accessible resources, said computer
program comprising: code for reading said descriptions; code for displaying items,
wherein each item is associated with a corresponding said descriptor component of
a said read description that has at least one said attribute; code for specifying
a query in terms of index descriptors; code for searching said descriptions of the
resources using said query; and code for locating said corresponding electronically-accessible
resources using said links associated with said displayed items.
[0019] According to still another aspect of the invention, there is provided a computer
readable medium comprising a computer program for utilising electronically-accessible
resources using descriptions of said resources, wherein the descriptions of said resources
have descriptor components, each said descriptor component comprises the association
of a feature of a said resource with a representative value for that feature, and
one or more of said descriptor components including a table of contents attribute
and one or more of said descriptor components including an index attribute, and wherein
said descriptions have links to corresponding said electronically- accessible resources,
said computer program comprising: code for reading said descriptions; code for displaying
a table of contents containing table of contents items, wherein each table of contents
item is associated with a corresponding said descriptor component that has a table
of contents attribute; code for selecting one said displayed table of contents item;
code for displaying an index containing index items, wherein each said displayed index
item is associated with a corresponding said descriptor component that has an index
attribute and that is associated with the said selected table of contents item; code
for selecting one or more index items in the displayed index; code for specifying
a said representative value or values for the one or more said selected index items;
code for searching said descriptions of the resources for said one or more selected
index items and their corresponding said specified representative value or values;
and code for locating one or more said descriptions of the resources corresponding
to said one or more selected index items and their corresponding said specified representative
value or values.
[0020] According to still another aspect of the invention, there is provided a computer
readable medium comprising a computer program for utilising an electronically-accessible
resource using a description of said resource, wherein the description of said resource
has descriptor components, each said descriptor component comprises the association
of a feature of said resource with a representative value for that feature, and one
or more of said descriptor components including a table of contents attribute and
one or more of said descriptor components including an index attribute, said computer
program comprising: code for reading said descriptions; code for displaying a table
of contents containing table of contents items, wherein each table of contents item
is associated with a corresponding said descriptor component that has a table of contents
attribute; code for selecting one said displayed table of contents item for the annotation;
code for displaying an index containing index items, wherein each said displayed index
item is associated with a corresponding said descriptor component that has an index
attribute and that is associated with the said selected table of contents item; code
for selecting one said displayed index item; code for associating said selected displayed
index item with said selected table of contents item; code for choosing a said representative
value for the selected index item; and code for associating said chosen representative
value with said feature which corresponds to said selected index item, wherein said
chosen representative value and its corresponding feature provide an annotation of
the resource.
[0021] According to still another aspect of the invention, there is provided a method of
selecting one or more descriptions or one or more descriptor components from a set
of descriptions, wherein said descriptions comprise one or more said descriptor components,
and each said description of said set of descriptions is associated with a corresponding
electronically accessible resource, said method comprising the steps of: specifying
a desired selection of descriptor components; generating a selection rule based on
said specified descriptor components, wherein said selection rule having a predetermined
pattern and action component, wherein the said predetermined pattern represents a
specified pattern of descriptor components and the said action specifies the action
to be performed when a said descriptor component in the descriptions of the set of
descriptions matches the predetermined pattern; reading said descriptions of the resources;
locating patterns of descriptor components in descriptions of said set of descriptions
in order to select descriptor components or descriptions in said set of descriptions
having said descriptor components which match the predetermined pattern; and performing
said specified action.
[0022] According to still another aspect of the invention, there is provided apparatus for
selecting one or more descriptions or one or more descriptor components from a set
of descriptions, wherein said descriptions comprise one or more said descriptor components,
and each said description of said set of descriptions is associated with a corresponding
electronically accessible resource, said apparatus comprising: means for specifying
a desired selection of descriptor components; means for generating a selection rule
based on said specified descriptor components, wherein said selection rule having
a predetermined pattern and action component, wherein the said predetermined pattern
represents a specified pattern of descriptor components and the said action specifies
the action to be performed when a said descriptor component in the descriptions of
the set of descriptions matches the predetermined pattern; means for reading said
descriptions of the resources;
means for locating patterns of descriptor components in descriptions of said set of
descriptions in order to select descriptor components or descriptions in said set
of descriptions having said descriptor components which match the predetermined pattern;
and means for performing said specified action.
[0023] According to still another aspect of the invention, there is provided a computer
readable medium comprising a computer program for selecting one or more descriptions
or one or more descriptor components from a set of descriptions, wherein said descriptions
comprise one or more said descriptor components, and each said description of said
set of descriptions is associated with a corresponding electronically accessible resource,
said computer program comprising: code for specifying a desired selection of descriptor
components; code for generating a selection rule based on said specified descriptor
components, wherein said selection rule having a predetermined pattern and action
component, wherein the said predetermined pattern represents a specified pattern of
descriptor components and the said action specifies the action to be performed when
a said descriptor component in the descriptions of the set of, descriptions matches
the predetermined pattern; code for reading said descriptions of the resources; code
for locating patterns of descriptor components in descriptions of said set of descriptions
in order to select descriptor components or descriptions in said set of descriptions
having said descriptor components which match the predetermined pattern; and code
for performing said specified action.
[0024] According to still another aspect of the invention, there is provided a method of
generating on an output device a presentation based on a predetermined selection of
resources, said method comprising the steps of: reading a description scheme for said
presentation, wherein the description scheme for said presentation uses a declarative
description definition language which contains definitions for descriptor components
of the description scheme; generating a description of the said presentation using
said description scheme and said predetermined selection of said resources; and generating
on said output device the said presentation based on the said description of the said
presentation and the predetermined selected resources.
[0025] According to still another aspect of the invention, there is provided a method of
generating on an output device a presentation based on a predetermined selection of
resources, said method comprising the steps of: reading a description scheme for said
presentation, wherein said description scheme contains definitions for descriptor
components of the description scheme, and each said descriptor component comprises
the association of a presentation attribute with a representative value for that attribute;
generating a description of the said presentation using said description scheme and
said predetermined selection of resources; and generating on said output device the
said presentation based on the said generated description of the said presentation,
the predetermined selected resources, and a set of presentation rules, which rules
specify characteristics of the style of said generated presentation, wherein said
set of presentation rules are associated with said description scheme.
[0026] According to still another aspect of the invention, there is provided apparatus for
generating on an output device a presentation based on a predetermined selection of
resources, said apparatus comprising: means for reading a description scheme for said
presentation, wherein the description scheme for said presentation uses a declarative
description definition language which contains definitions for descriptor components
of the description scheme; means for generating a description of the said presentation
using said description scheme and said predetermined selection of said resources;
and means for generating on said output device the said presentation based on the
said description of the said presentation and the predetermined selected resources.
[0027] According to still another aspect of the invention, there is provided apparatus for
generating on an output device a presentation based on a predetermined selection of
resources, said apparatus comprising: means for reading a description scheme for said
presentation, wherein said description scheme contains definitions for descriptor
components of the description scheme, and each said descriptor component comprises
the association of a presentation attribute with a representative value for that attribute;
means for generating a description of the said presentation using said description
scheme and said predetermined selection of resources; and means for generating on
said output device the said presentation based on the said generated description of
the said presentation, the predetermined selected resources, and a set of presentation
rules, which rules specify characteristics of the style of said generated presentation,
wherein said set of presentation rules are associated with said description scheme.
[0028] According to still another aspect of the invention, there is provided a computer
readable medium comprising a computer program for generating on an output device a
presentation based on a predetermined selection of resources, said computer program
comprising: code for reading a description scheme for said presentation, wherein the
description scheme for said presentation uses a declarative description definition
language which contains definitions for descriptor components of the description scheme;
code for generating a description of the said presentation using said description
scheme and said predetermined selection of said resources; and code for generating
on said output device the said presentation based on the said description of the said
presentation and the predetermined selected resources.
[0029] According to still another aspect of the invention, there is provided a computer
readable medium comprising a computer program for generating on an output device a
presentation based on a predetermined selection of resource, said computer program
comprising: code for reading a description scheme for said presentation, wherein said
description scheme contains definitions for descriptor components of the description
scheme, and each said descriptor component comprises the association of a presentation
attribute with a representative value for that attribute; code for generating a description
of the said presentation using said description scheme and said predetermined selection
of resources; and code for generating on said output device the said presentation
based on the said generated description of the said presentation, the predetermined
selected resources, and a set of presentation rules, which rules specify characteristics
of the style of said generated presentation, wherein said set of presentation rules
are associated with said description scheme.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Embodiments of the invention are described with reference to the accompanying drawings,
in which:
Fig. 1A shows a flow diagram of a method of generating a description of a resource
in accordance with an embodiment;
Fig. 1B shows a flow diagram of a method of processing a description of a resource
in accordance with another embodiment;
Fig. 1C shows a flow diagram of a method of encoding a description of a resource in
accordance with another embodiment;
Fig. 1D shows a flow diagram of a method of decoding an encoded description of a resource
in accordance with another embodiment;
Figs. 2A shows a flow diagram of a prior art method of generating a document object
model;
Fig 2B show a flow diagram of a method of generating a Description Object Model in
accordance with another embodiment;
Fig. 3 shows a UML class diagram showing core elements of the Dynamic Description
Framework(DDF) data model;
Fig. 4 shows a schematic drawing depicting the processing model of an exemplary description
according to a DDF;
Fig. 5 shows a schematic drawing depicting the processing model of another exemplary
description according to a DDF;
Fig. 6 shows a schematic drawing depicting the relationship between a description
scheme (Document Type Definition) and descriptions( XML documents);
Fig. 7A is a flow diagram of a method of generating a description of a resource in
accordance another embodiment;
Fig. 7B is a flow diagram of a method of processing a description of a resource in
accordance another embodiment;
Fig. 8 shows an example of the use of a descriptor handler in generating video segment
description using camera metadata that is saved to the video;
Fig. 9 shows an example of the use of descriptor handlers to support a query-by-example
over remote image databases;
Fig. 10 shows an example of the use a descriptor handler for encoding/decoding;
Fig. 11 shows an example of descriptor handlers implemented as Java classes;
Fig. 12 is a flow diagram of a method of extending a description of a resource in
accordance with another embodiment;
Fig. 13 is a flow diagram of a method of using rules to add or remove attributes of
a Description Scheme that are used to control the presentation of a description of
a resource in accordance with another embodiment;
Fig. 14 is a flow diagram of a method of selecting one or more descriptions or part
of one or more descriptions of a resource in accordance with another embodiment;
Fig. 15 is a flow diagram of a method of translating a description of a resource in
accordance with another embodiment;
Fig. 16 shows a schematic diagram Digital Video Browser System in accordance with
another embodiment;
Fig. 17 shows an implementation of the Digital Video Browser System in a remote handheld
device in accordance with another embodiment;
Fig. 18 shows an alternative implementation of the Digital Video Browser System in
a remote handheld device in accordance with another embodiment;
Fig. 19 is a block diagram of a general-purpose computer for implementing any one
or more said methods; and
Fig. 20 shows a schematic diagram of an Media Browser System in accordance with another
embodiment.
[0031] Where reference is made in any one or more of the accompanying drawings to steps
and/or features, which have the same reference numerals, those steps and/or features
have for the purposes of this description the same function(s) or operation(s), unless
the contrary intention appears.
BRIEF DESCRIPTION OF THE APPENDICES
[0032] Embodiments of the invention are also described with reference to the appendices,
in which:
Appendix A shows core DDF element definitions;
Appendix B shows an example description scheme for an Australian Football League Game;
Appendix C shows an example description generated from the description scheme in Appendix
B;
Appendix D shows a digital video resource description scheme;
Appendix E shows an example description generated from the video description scheme
in Appendix D;
Appendix F shows presentation rules for the video description scheme in Appendix D;
Appendix G shows a digital video library description scheme;
Appendix H shows an example description generated from the digital video library description
scheme in Appendix G;
Appendix I shows video presentation description scheme;
Appendix J shows an example description generated from the video presentation description
scheme in Appendix I; and
Appendix K shows DOM element nodes.
DETAILED DESCRIPTION
[0033]

1. INTRODUCTION
[0034] For a better understanding of the embodiments, an introduction (Section 1) including
a brief review of terminology (Section 1.1) is first undertaken, then there is provided
a discussion of relationships between components of descriptions (Section 1.2), the
DDF (Section 2), the serialisation syntax specification (Section 3), and the DesOM
API specification (Section 4) used in the embodiments. A more detailed description
of the embodiments is then given in Sections 6 to 15.
[0035] Some portions of the detailed descriptions which follow are explicitly or implicitly
presented in terms of algorithms and symbolic representations of operations on data
within a computer memory. These algorithmic descriptions and representations are the
means used by those skilled in the data processing arts to most effectively convey
the substance of their work to others skilled in the art. An algorithm is here, and
generally, conceived to be a self-consistent sequence of steps leading to a desired
result. The steps are those requiring physical manipulations of physical quantities.
Usually, though not necessarily, these quantities take the form of electrical or magnetic
signals capable of being stored, transferred, combined, compared, and otherwise manipulated.
It has proven convenient at times, principally for reasons of common usage, to refer
to these signals as bits, values, elements, symbols, characters, terms, numbers, or
the like.
[0036] It should be borne in mind, however, that all of these and similar terms are to be
associated with the appropriate physical quantities and are merely convenient labels
applied to these quantities. Unless specifically stated otherwise as apparent from
the following discussions, it is appreciated that throughout the present invention,
discussions utilising terms such as "processing", "computing", "generating", "creating",
"operating" "communicating", "rendering", "providing", and "linking" or the like,
refer to the action and processes of a computer system, or similar electronic computing
device, that manipulates and transforms data represented as physical (electronic)
quantities within the computer system's registers and memories into other data similarly
represented as physical quantities within the computer system memories or registers
or other such information storage, transmission or display devices.
[0037] The present invention also relates to apparatus for performing the operations herein.
This apparatus may be specially constructed for the required purposes, or it may comprise
a general purpose computer selectively activated or reconfigured by a computer program
stored in the computer. The algorithms and displays presented herein are not inherently
related to any particular computer or other apparatus. Various general purpose machines
may be used with programs in accordance with the teachings herein, or it may prove
convenient to construct more specialised apparatus to perform the required method
steps. The structure of a conventional general purpose computer will appear from the
description below.
[0038] In addition, the present invention also relates to a computer program product comprising
a computer readable medium including a computer program for implementing the preferred
methods. The computer readable medium is taken herein to include any transmission
medium for transmitting the computer program between a source and a designation. The
transmission medium may include storage devices such as magnetic or optical disks,
memory chips, or other storage devices suitable for interfacing with a general purpose
computer The transmission medium may also include a hard-wired medium such as exemplified
in the Internet system, or wireless medium such as exemplified in the GSM mobile telephone
system. The computer program is not intended to be limited to any particular programming
language and implementation thereof. It will be appreciated that a variety of programming
languages and implementations thereof may be used to implement the teachings of the
invention as described herein.
1.1 Terminology
1.1.1 Content
[0039] Content is defined to be information, regardless of the storage, coding, display,
transmission, medium, or technology. Examples of content include digital and analog
video (such as an MPEG-4 stream or a video tape), film, music; a book printed on paper,
and a web page.
1.1.2 Resource
[0040] A resource is a particular unit of the content being described. Examples of a resource
include an MPEG-1 video stream, a JPEG-2000 image, and a WAVE audio file.
1.1.3 Feature
[0041] A feature is a distinctive part or characteristic of the resource which stands for
something to somebody in some respect or capacity. A feature can be derived directly
(ie., extracted) from the content (eg., dominant colour of an image) or can be a relevant
characteristic of the content, Examples of features include the name of the person
who recorded the image, the colour of an image, the style of a video, the title of
a movie, the author of a book, the composer of a piece of music, pitch of an audio
segment, and the actors in a movie.
1.1.4 Descriptor
[0042] A descriptor associates a representation value to a feature, where the representation
value can have an atomic or compound type. The representation value can have an atomic
or compound type An atomic type is defined as one of a basic set of predetermined
data types (eg., integer, string, date, etc.). A compound type is defined to be a
collection of one or more descriptors. The descriptor comprises a feature - representation
value pair, where the representation value is associated with the feature. Example
descriptors having atomic types include:
Feature = Author, Representation Value (string) = "John Smith";
Feature = DateCreated; Representation Value (date) = "1998-08-08".
An example descriptor having a compound type is;
Feature = Colour; Representation Value = ColourHistogramDescriptor.
1.1.5 Description
[0043] A description is a descriptor having a compound type pertaining to a single resource.
1.1.6 Description Scheme
[0044] A description scheme is a set of descriptor definition and their relationships (associations,
equivalence, specialisations, and generalisations). The descriptor relationships can
be used to directly express the structure of the content or to create combinations
of descriptors which form a richer expression of a higher-level concept. A description
Scheme includes within its scope a comprehensive set of description schemes.
1.2 Descriptor Relationships
[0045] In order to express the information required for a description scheme, the DDF preferably
provides a minimum set of descriptor relationships. This minimum set includes:
- Generalisation/specialisation relationships,
- Association relationships,
- Equivalence relationships,
- Spatial, temporal and conceptual relationships,
- Navigational relationships.
[0046] The generalisation/specialisation relationships specify that a particular descriptor
is a more specific or more general form of another descriptor and hence can be viewed
by a processing application as such. For example, a cat is a type of animal, and hence
a search engine searching for occurrences of animal descriptors should also select
descriptions which contain "cat" descriptors.
[0047] Association relationships are defined here to include descriptor containment and
sequence and cardinality of occurrence. These relationships provide contextual information
for a given descriptor and are necessary in order to provide a context in which a
particular descriptor can be interpreted by an application. For example, a "Shot"
descriptor which is contained within a "VideoScene" descriptor in a video description
scheme would be interpreted differently from a "Shot" descriptor in another context
in a sound effects description scheme.
[0048] An equivalence relationship is a form of a classification relationship where the
relation is not necessarily of a generalisation/specialisation nature. Equivalence
relationships are desirable between languages (ie., inter-language) and within a language
(ie., intra-language). Typically equivalences will require the definition of synonyms
(where two descriptors are equivalent) and quasi-synonyms (where two descriptors are
equivalent to some specified extent). Also there is a need to define equivalence relationships
between non-textual values (eg., mean R, G and B values in an image) and a textual
representative value (eg., red, green, etc.), and vice-versa.
[0049] Spatial, temporal and conceptual relationships between descriptors in a description
may also be used. These relationships support the description of neighbouring objects
in an image, sequential segments in a video scene, and similar concepts in a description.
[0050] Navigation relationships between descriptors are also desirable. Usage of descriptions
will often involve navigation between a component of the description and an associated
spatio-temporal extent in the resource (such as a key frame in a video resource).
[0051] Considered together these relationships can to some extent provide a level of semantic
interoperability between different description schemes. Further levels of semantic
interoperability could also be achieved at the application level.
1.3 Overview of Embodiments of Methods
[0052] The methods described herein are specific examples of a generalised form of a method
for generating and processing descriptions of resources utilising a Dynamic Description
Framework (DDF). This framework provides an object model, a platform- and language-neutral
application programming interface (API) and a serialisation syntax for use in the
description of resources, in particular audiovisual resources. The preferred DDF incorporates
the benefits of declarative description of content with procedural methods for the
creation and processing of descriptions and components of descriptions.
[0053] Fig. 1A shows an overview of a method of generating a description of an electronically-accessible
resource. In this method, a description scheme (DS) 100A is read by a description
generator 106A which in turn generates a representation 108A of a description 107A
of the resource in memory. This representation 108A is an instance of the Description
Object Model (DesOM) of the DDF. The representation 108A of the description 107A can
be serialised as an XML document 110A for the purposes of storage and transport. Preferably,
both the description scheme 100A and the serialised description 110A are textual and
are both readable by machines and humans. It is further preferable that the description
scheme 100A is provided with associated procedural code, called DescriptorHandler(s),
so as to provide operations/processes which can unambiguously provide or generate
descriptive information or other actions on the resource 104A. For example, the method
in one operating mode is able to automatically generate a description 107A of the
resource 104A. In this operating mode, the processes of the DescriptorHandler(s) operate
on the resource 104A to generate a description 107A of that particular resource 104A.
These description schemes 100A and descriptions 107A are defined in terms of the abovementioned
DDF.
[0054] Fig. 1B shows an overview of the method of processing a description of a resource.
In this method, a serialised description 100B is parsed by a processor 102B which
in turn generates a representation 104B of the description in memory. The representation
104B is an instance of the DesOM of the DDF. Such a serialised description 100B may
be generated in accordance with the method of Fig. 1A. Preferably, the processor 102B
and description generator 106A (Fig. 1) are incorporated as one unit. The serialised
description 100B refers to a description scheme 106B which may in turn refer to a
number of DescriptionHandler(s) 108B. The serialised description 100B also refers
to the resource 110B which the description describes. In this method, a set of rules
may be applied to the DesOM representation of the description (D) 104B to generate
a modified DesOM representation of the description 112B. (The term D+ has been used
to indicate the modified DesOM representation of the description 112B in Fig. 1B.]
The modified DesOM representation of the description 112B can be serialised as an
XML document. This set of rules is defined by the Description Scheme 106B. The DescriptorHandler(s)
108B provide further processing of the DesOM representation of the description 114B
or the modified DesOM representation of the description 116B. In one operating mode,
the processing method is able to compute the similarity between resources 110B. In
this mode, the DescriptorHandler provides a process for computing similarity between
descriptions of resources. The processing method is further adapted to apply a set
of rules 118B to the DesOM representation of the description 104B. The set of rules
118B provides one or more associated actions on the description, 104B depending on
the presence of pre-determined components of the serialized description 100B, The
resultant output of these actions is itself a representation of a description which
conforms to the DesOM 112B. Further, a description scheme may be read into memory
and a set of rules provided for performing one or more associated actions on the description
scheme itself. These sets of rules are able to extend resource descriptions; translate
resource descriptions; select one or more specific descriptions according to a query;
visually present resource descriptions and many other actions.
[0055] Fig. 1C shows an overview of the method of encoding a description of a resource.
In this method, a description scheme (DS) 104C is read by a description generator
108C which in turn generates a representation 110C of a description of the resource
in memory. This representation 110C is an instance of the DesOM of the DDF. The description
scheme 104C is provided with an associated procedural code, by means of a DescriptorHandlers
(DH), so as to provide an encoding procedure 114C on the DesOM representation 110C.
The encoding procedures encodes the DesOM representation 110C to provide an encoded
DesOM 112C. The encoded DesOM representation 112C of the description can be serialised
as an XML document for the purposes of storage and transport. The encoding procedure
is preferably utilised for compression and/or encryption purposes.
[0056] Fig. 1D shows an overview of a method of decoding an encoded description of a resource.
This method has as its input a serialised description 104D which has been encoded
by the method of Fig. 1C. In this method, the serialised description 104D is parsed
by a processor 110D which in turn generates an encoded representation 112D of the
description in memory. The representation 112D is an instance of the encoded DesOM.
The description scheme 106D provided with associated procedural code, called descriptor
handlers, so as to provide the decoding operation 114D which can decode the encoded
DesOM representation 112D so as to provide the decoded representation 116D of the
description in memory. The representation 116D is an instance of the DesOM of the
DDF.
2. Dynamic Description Framework
2.1 Overview
[0057] The preferred DDF attempts to incorporate the benefits of declarative description
of content with procedural methods for the creation and processing of descriptors.
It comprises an object model, an API for the processing of descriptions, and a serialisation
syntax. The DDF can be used to adequately describe content using these components.
[0058] The object model provides the core semantics of the description and is based on the
descriptor entity. This model has the advantage that the containment relationship
is inherent in the model. This containment relationship is particularly important
in the description of audiovisual resources for two reasons. First, the structure
of many audiovisual resources has an inherent hierarchical structure (eg., a video
clip contains shots which contain key frames, etc.). Second, the representation values
for many descriptors can be complex datatypes that can be represented in a hierarchical
fashion (eg., a histogram contains bins which contain frequencies). The object model
of the preferred DDF is called the Description Object Model (DesOM). It is discussed
in Section 2.2.
[0059] The preferred DDF also uses an API for the processing of descriptions. This enables
applications and tools to perform further processing (eg., transformations, presentations,
etc.) on serialised descriptions. The preferred API, which is described further in
Section 2.3, is based on the Document Object Model called the DOM, which has been
standardised by the W3C for use with XML documents.
[0060] The DesOM API also enables the application of rule-based processing, which can be
used to:
- Extend a description by inferring the presence of additional descriptors based on
the existence or absence of stored descriptors;
- Influence/control the presentation of a description;
- Select descriptions or components of descriptions;
- Translate a stored description into another language on the basis of requirement;
- Transform a description to use a new description scheme.
This rule-based processing is described in more detail in Sections 7 to 11.
[0061] The tree-based structure of the DesOM (and for that matter, the DOM) is an appropriate
representation of hierarchically structured data such as the preferred data model.
[0062] The DDF preferably uses a serialisation syntax for the purposes of storage and transport
of descriptions and description schemes. Serialised descriptions can be parsed into
an instance of the DesOM. In addition, the serialisation syntax provides a means for
expressing the descriptor relationships detailed in Section 1.2. The syntax of XML
Document Type Definitions (DTDs) is used to express description schemes and XML documents
to serialise individual descriptions. The expression syntax of both description schemes
and individual descriptions is referred to as the serialisation syntax.
[0063] XML is used as the serialisation syntax because of its inherent ability to express
the containment relationship and its increasing acceptance as a form for the transmission
of structured electronic data. A description scheme can be represented using the grammar
of an XML DTD in which the individual element definitions represent the definitions
of the descriptors and their relationships in the description scheme. Individual descriptions
can be serialised as XML documents that conform to the DTD containing the relevant
description scheme. Section 2.4 describes how the preferred object model and the required
descriptor relationships are expressed using the serialisation syntax.
[0064] The use of XML as the serialisation syntax enables the possibility of DDF conformant
descriptions to be interpreted, in theory, at two levels. First, any serialised description
is able to be interpreted at an XML syntactical level. At this level the description
could be parsed into an object model such as the DOM and a search/filter engine with
no knowledge of the DDF could interpret the description in terms of its textual content
(ie., the semantics of the DDF's object model are not used for the description's interpretation).
Alternatively, the description could be parsed at a more semantic level by using the
DDF object model, the DesOM, rather than the DOM.
[0065] In practice, however, it is necessary to parse the description scheme expressed using
the XML DTD syntax into an XML DTD where descriptor specialisation/generalisation
relationships are validated and explicitly realised (see Section 2.4.1.1 for further
details). This step is necessary because no level of subclassing or inheritance is
provided for in Version 1.0 of XML. We refer to this step as DDF interpretation and
the process performing the step is a DDF Interpreter. To differentiate between the
DTD containing the DDF definition of a description scheme and the DTD to which the
description (ie., XML Version 1.0 document) conforms, we name the DDF DTD using an
extension "ddf" rather than "dtd" as is typically used for an XML DTD.
[0066] A serialised description can then be parsed and represented using the DOM from its
conformant DTD (ie., the DTD stored using the extension "dtd") by a standard XML Processor.
This processor needs no knowledge of DDF and the content of the descriptions can be
accessed at a textual level. [Textual access to the description could also be achieved
by simply scanning the description (XML document) or using XML Processors that are
not based on the DOM (eg., SAX)] Alternatively, a DDF Processor can parse the serialised
description and represent it using the DesOM from the DTD containing the description
scheme expressed using DDF (ie., the DTD stored using the extension "ddf"). The first
step of the latter process is the one of DDF interpretation.
[0067] This process of two level interpretation is depicted in Figs. 2A and 2B, which show
how different semantic levels of access can be obtained from a (DDF) description serialised
using the XML syntax. The DesOm and DOM are similar in that both are tree-based structures.
However, the DesOM differs from the DOM in that DesOM contains element nodes which
have a richer interface than the corresponding element nodes in the DOM. In addition,
the element nodes of the DesOM can have an associated DescriptorHandler (H) which
provides procedures that are relevant to the element.
2.2 Object Model
2.2.1 Overview
[0068] The object model adopted for the preferred DDF is based on the definition of a core
Descriptor object. As defined in Section 1.1.4, a descriptor can be viewed as an "feature-representative
value" pair. The representative value can be of atomic type (eg., integer, string,
date, etc.) or compound type, where a compound type is a collection of one or more
descriptors. The object model is represented by the UML class diagram in Fig 3. [Note
that the use of capitals in Descriptor and Description implies the objects as defined
in Figure 3 rather than the general terms defined in Section 1.1.4.]
[0069] A Description object is defined as a specialisation of a Descriptor in which all
the contained Descriptors pertain to a single resource. Description schemes will contain
definitions of descriptors and descriptions which are specialisations of the core
Descriptor and Description objects, respectively.
[0070] In the preferred object model descriptors can represent properties and relationships
of their parent descriptors. For example, a Region Descriptor for a Region Adjacency
Graph of an image could contain a Label Descriptor (containing a textual representative
value) and a Neighbours Descriptor (containing a representative value comprising a
list of references to other Region Descriptors). In this example, the Label Descriptor
can be viewed as representing a property of a region and the Neighbours Descriptor
as representing a spatial relationship involving the region. Descriptors representing
relationships (eg., spatial, temporal, conceptual) typically have representative values
that comprise one or more references to other descriptors in the description. In Section
2.4.1.4, a standard set of descriptors are proposed to express spatial, temporal and
conceptual relationships.
2.2.2 Descriptor Class
[0071] Each Descriptor has an associated id, language code and dataType enumeration. The
id attribute provides each Descriptor with a unique identity. This identity can be
used to reference other Descriptor objects in a description. The language code attribute
specifies the language of any text in the Descriptor's representative value. The dataType
enumeration provides the data type of the representative value if that value is atomic
(ie., not composed of other descriptors; see Section 2.2.3). Each Descriptor object
can also be associated with a Descriptor Handler which provides procedural methods
associated with the Descriptor (see Section 2.2.4).
[0072] Implementations of the preferred DDF object model can implement to various extent
the descriptor relationships detailed in Section 1.2. This approach means that different
implementations can utilise the properties of the particular serialisation syntaxes
adopted. Section 2.4.1 describes in detail how the descriptor relationships detailed
in Section 1.5 are realised using an XML serialisation syntax.
2.2.3 Atomic Descriptor Value Class
[0073] A Descriptor's representative value can be atomic or compound (ie., composed of other
Descriptor objects). If it is atomic, then the value is stored in an Atomic Descriptor
Value object as a string object. The data type of this atomic value is interpreted
using the dataType attribute of the parent Descriptor object. Therefore the extent
to which data typing is provided depends on the dataType attribute for particular
implementations of this data model. For example, refer to Section 2.4.2 for data typing
implementation details using the preferred XML serialisation syntax.
[0074] The Atomic Descriptor Value could also be represented by a data attribute of the
Descriptor class. The Atomic Descriptor Value is represented here as a class because
of the one-to-one correspondence of this entity to a Text node in the DOM (and AtomicDescriptorValue
node in the DesOM; see Section 4.1.3).
2.2.4 Descriptor Handler Class
[0075] In the preferred DDF, a Descriptor Handler is a class which provides procedural methods
that apply to the Descriptor. The methods of the Descriptor Handler preferably satisfy
a specified interface. The Descriptor Handler classes can provide methods for the
creation of a Descriptor's representative value (or content) and the computation of
the similarity between two descriptors of the same type (ie., that use the same Descriptor
definition and hence Descriptor Handler). There is no reason why this set of procedures
could not be extended if required. Fig. 3 details some examples of the Descriptor
Handler methods provided in the preferred implementation of the DDF.
[0076] The methods mentioned above are preferably implemented as static (class) methods
that satisfy a specified interface (eg., see Section 4.1.2). The role of the Descriptor
Handler is to provide unambiguous procedures for the generation and processing of
Descriptors. The ability to pass parameters to Descriptor Handler methods is discussed
in Section 3.1.2.1 with respect to the use of XML as a serialisation syntax.
[0077] Preferably, the programmatic interface for a Descriptor Handier is fixed. In other
embodiments, the interface could be specified as an attribute of the Descriptor class
or specified for the description scheme. These alternative embodiments enable the
Dcscriptor Handler interface to be customised for particular description schemes.
[0078] Descriptor Handler methods can also be provided for the encoding and decoding of
a Descriptor's representative value. Encoding methods could be provided in order to
either compress (ie., reduce in size) the serialised description and therefore more
efficiently store and transport the description, or alternatively to encrypt the Descriptor's
representative value.
[0079] In the case of encoding for compression, the encoding method could vary depending
on the type of data to be encoded. For example, a Descriptor with a textual representative
value could use a text compression method (eg., LZW), whereas a Descriptor that represented
a colour histogram structure of an image resource may encode the bin frequencies of
the histogram using a form of entropy encoding (ie., most commonly occurring frequencies
are represented by codewords requiring fewer bits). Encoding for encryption could
be used to allow only privileged users access to the Descriptor. Standard encryption
methods (eg., public key encryption) could be used.
2.2.5 Description Class
[0080] The Description has some additional attributes to those of the Descriptor. It has
an associated resource which contains either the URI or ENTITY of the item of content
being described. It also contains a reference to the data when that resource was last
modified and an attribute that contains the URIs or ENTITIES of sets of rules that
can be applied to the Description. Rule-based processing of descriptions is discussed
further in Section 7.
[0081] Since a Description object is defined as a specialisation of the Descriptor object,
Description objects can be treated as Descriptor objects in other descriptions (ie.,
the attributes of the Description are ignored). In an alternate data model, the Description
object can contain both Descriptor and Description objects. With this data model Description
objects can exist in another tree of Descriptors and refer to resources other than
that of the root description.
[0082] Another alternative implementation could use a data model which did not include a
Description object, since a Description is essentially the same as a Descriptor having
a compound representative type. In this case the additional attributes of the Description
(ie resource, dateResourceLastModified and ruleSets) would be treated as attributes
of the Descriptor. With this data model the resource would only need to be specified
at the top of the Descriptor tree where it was relevant.
2.3 API for Processing of Descriptions
[0083] The inherent containment property of the core Descriptor object is represented by
a tree-based processing model (ie., parent-children data model) where each node of
the tree is either a Descriptor or Atomic Descriptor Value object. [Atomic Descriptor
Value objects can only exist as leaf nodes of the tree.) The DesOM also contains references
and navigational links between nodes in the tree. References are typically used to
indicate relationships (eg., spatial, temporal and/or conceptual) between Descriptor
objects. Navigational links are used to provide browsing properties for the description
and enable linking between Descriptor objects in the description and spatio-temporal
extents in the resource (eg., a particular frame in the video stream being described).
A schematic depicting the description processing model is shown in Fig. 4.
[0084] For a description to conform to the preferred DDF, the root of the DesOM must be
a Description object. In other words, the root must specify the resource to which
the description refers. Since a Description object is just a specialisation of the
Descriptor object, any Description object can become a sub-tree of another Description
object. In other words, a new Description object can be created from a set of related
Description objects. This process is shown in Fig. 5.
[0085] The DesOM extends the DOM by providing the required generalisation/specialisation
relationships for descriptors, data typing for atomic representative values for descriptors,
DescriptorHandlers (H) and reference and navigational links. The DOM provides a standard
set of objects for representing XML documents, a standard model of how these objects
can be combined, and a standard platform- and language-neutral interface for accessing
and manipulating them. The DOM representation of an XML document is a tree structure
where the content of an element is represented as child nodes of the element. The
DOM specifies interfaces which can be used to manage XML documents. In other words,
it can be implemented in any (or nearly all common) programming languages.
[0086] Similarly only interfaces are specified for the DesOM. These interfaces can be used
to process XML documents that are DDF conformant. Just as an XML (DOM) Processor must
implement a DOM interface, a DDF Processor must implement a DesOM interface (see Fig.
2). As mentioned in Section 2.1, a DDF Processor first performs an interpretation
step in which the generalisation/specialisation relationships of descriptors is validated
and processed in a Version 1.0 XML DTD form. [Invalid subclassing in the description
scheme expressed using the DDF and the syntax of XML DTDs should result in a description
scheme parsing error.] The DDF Processor can then either parse the description into
a DOM and transform that structure into a DesOM or parse the description directly
into a DesOM.
[0087] Essentially the DesOM differs from the DOM in that element and text nodes are replaced
by the richer interfaces of Descriptor and Atomic Descriptor Value nodes. Interfaces
for these nodes are described in Section 4 and section 6.3. A basic DesOM implementation
could provide just that interface, however a more expansive implementation might provide
some level of interpretation of the reference and navigational relationships. For
example, a set of spatial, temporal and conceptual relationships could be defined
for the DDF (see Section 3.1.3) and these could be interpreted at the DesOM level.
[0088] Implementations of the DesOM could optionally execute Descriptor Handler methods
to create, encode or process descriptors. For example, a DesOM implementation might
implement a Descriptor Handler's method to create the content for a Descriptor if
the content did not already exist.
[0089] The DesOM provides a basis for the further processing of descriptions. The tree-structure
of the DesOM makes it amenable to rule-based processing where rules consist of a pattern
and an associated action. Such processing could be performed by tools which implement
the DesOM interface to process DDF descriptions. Rule-based processing is discussed
further in Section 7 to 11.
2.4 Serialisation Syntax
[0090] The serialisation syntax preferably used for the storage and transport of descriptions
and description schemes is XML Version 1.0. The XML standard was developed as a subset
of Standard Generalised Markup Language (SGML). An XML document contains one or more
elements, the boundaries of which are either delimited by start and end tags, or by
an empty-element tag. Each clement is identified by its name, sometimes also called
its "generic identifier" (GI) and may have a set of attribute specifications. Each
attribute specification has a name and a value. For further details on the XML Version
1.0 standard, reference is made to the W3C website HTTP://www.w3.org/TR/1998/REC-xml-19980210.
[0091] The preferred DDF uses a set of core elements which can be defined in an DDF Core
DTD. A SGML-like DTD syntax is used to define element types and their associated attributes
(as specified in the Version 1.0 XML standard). Each description can be represented
by an XML document This document (ie., the description) refers to the DTD (ie., the
description scheme) to which the description conforms. In other words the description
is of the type specified by the DTD (see Fig. 6)
[0092] The DDF Core DTD needs to provide definitions for the core elements required for
the expression of the object model. The element definition that is central to the
DDF is that of the Descriptor element. All descriptors can be defined as subclasses
(specialisations) of this core element. For example, although a Description is defined
to be a collection of descriptors pertaining to a single resource it is defined as
a subclass of the Descriptor element. Other subclasses of the Descriptor element are
used to provide linking functionality between the descriptors and the resources being
described (see Section 3.1.4).
[0093] The data modelling requirements of the DDF are more extensive than those provided
by the XML Specification version 1.0. Specifically the serialisation syntax of the
DDF is able to:
- Express the required descriptor relationships (see Section 2);
- Provide data typing for the (atomic) representative value of a descriptor;
[0094] These requirements are addressed in Sections 2.4.1 and 2.4.2 with respect to using
Version 1.0 of the XML standard as the serialisation syntax.
2.4.1 Expression of Descriptor Relationships
2.4.1.1 Generalisation/Specialisation Relationships
[0095] Version 1.0 of the XML specification does not provide for the specification of generalisation/specialisation
relationships. In addition, subclassing and inheritance in marked up documents is
not well-defined. An element type is a subclass (specialisation) of another element
type, the superclass, if it is substitutable wherever the superclass element occurs
and is defined to be a subclass of the superclass. It is not essential for an element
to be defined as a subclass of another element. The superclass can be viewed as a
generalisation of the subclass. The notion of inheritance can be viewed as a code-saving
mechanism which allows one element type to get (inherit) the properties of another
element type "for free".
[0096] The preferred subclassing/inheritance guidelines for single subclassing/inheritance
is described below in Sections 2.4.1.1.1 to 2.4.1.1.3. Multiple inheritance can be
extended from the single subclassing/inheritance.
2.4.1.1.1 Content Model Inheritance
[0097] A subclass should faithfully implement a base class's interface. Therefore, if a
base class has a content model of "ANY" then a subclass can have either an "ANY" content
model or a more restricted content model. This is necessary for the subclass to be
substitutable for the parent class. This is a somewhat different scenario from object
oriented programming (OOP) where a subclass must accept any input that its super (parent)
class can. The content model of an element should be viewed as "output" not "input".
If each element is considered as an object having methods to retrieve its content,
then a subclass must also be able to satisfy these methods. Each element type in a
content model can be viewed as having a role and the roles of a subclass's content
model must . match up with those of its parent class. A subclass cannot make more
flexible or extend components of the content model of its parent class, however it
can implement new child elements that will be ignored when that element is treated
as its parent class.
[0098] For example, if AA, BB and CC are subclasses of A, B and C, respectively and A has
a content model of (B, C) then the following are all valid content models of AA; (BB,
CC), (B, C), (BB, C) and (B, CC). The content models (B, C, D), (BB, CC, D) and (D,
B, C) are also valid content models for AA because they match "roles" for (B), (C)
and (B, C). In addition element, AA can contain child element D which will not be
visible if element AA is to be treated as an instance of element A. The content models
(B) and (C) are invalid because of the "role" of (B, C) in the content model of A
is not matched.
[0099] It would be possible to allow the content model for a subclass to be left unspecified
in which event the subclass's content model would default to be that of the superclass.
Preferably, unspecified content models should not be allowed as they do not represent
a valid construct using XML/SGML DTD syntax.
2.4.1.1.2 Attribute Inheritance
[0100] The same subclass and inheritance notions apply to attributes, however attributes
are more intrinsically amenable to concepts of subclassing than content because they
are "random access" in some sense as are methods in OOP. A subclass can declare new
attributes which are essentially ignored when the subclass is treated as it parent
class. However, a subclass cannot extend, or make more flexible, attributes of the
parent class.
[0101] The attribute defaults are only considered when assessing whether an attribute definition
has or has not extended that of its parent class. Consequently a subclass and its
specified superclass should have the same attribute type, and only the attribute default
be further restricted in the subclass. Valid restrictions of attribute default definition
are as in Table 1. In addition, if the superclass has a default declaration of "#FIXED"
and the value of the default can be interpreted as an element name then preferably
the value of the default can be further restricted to a be a subclass of that element
name.
2.4.1.1.3 Implementation Details
[0102] In order to implement this subclassing/inheritance model using Version 1.0 of the
XML Specification and the DOM, the superclass (or superElement) for an element is
specified as an attribute in the element's defined attribute list. It is believed
that this is not ideal and that subclassing information should be part of the element's
definition. For example, the keyword "TYPEOF" has been suggested as a means of representing
subclassing information (ie., 〈!ELEMENT Cat TYPEOF Animal〉).
[0103] The subclassing/inheritance implied by the use of the superElement attribute needs
to be interpreted and validated against the provided guidelines for subclassing/inheritance.
Failure to conform to these guidelines should result in a description scheme parsing
error. Also, in order for a serialised DDF description to be a valid XML document,
the description needs to conform to a valid XML DTD. Therefore the DDF description
scheme that is expressed using the syntax of XML DTDs needs to be parsed to create
an XML DTD in which all the inheritance aspects of the subclassing relationships are
processed. This involves:
- Making explicit content models which depend on subclassing (this may involve extending
content models so that they represent valid XML DTD content models in the absence
of subclassing semantics);
- The addition of inherited attribute definitions to subclassed Descriptor definitions.
2.4.1.2 Equivalence Relationships
[0104] The location of described resources can be achieved by the method by formulating
requests directly based on a description scheme or by more unstructured queries in
which the contents of a description scheme are unknown. Typically the former approach
will result in a more satisfactory result because the query is specifically formulated
for the form of the descriptions. However, in some cases a query might be formulated
without a (complete) knowledge of a description scheme (and hence use different terms
than those used in the description scheme) or in a language other than that used by
particular descriptions.
As highlighted in Section 1.2 there are three types of equivalences:
- Intra-language equivalences (ie., synonyms or quasi-synonyms);
- Inter-language equivalences (ie., translations);
- Inferred equivalences between textual and non-textual representative values.
Known intra-language equivalences could be incorporated into a descriptor's definition
using an
alias or
sameAs attribute for elements. However, applications and tools that provide a level of intra-language
equivalence interpretation exist and therefore it was considered unnecessary to provide
this functionality. Separate search/query/filter engines can ultimately provide some
level of intra-language equivalence interpretation.
[0105] It is desirable to provide a means for inter-language equivalence as queries will
not always be formulated in the same language as the description. Although some degree
of redundancy can be tolerated in a description scheme (ie., descriptors in different
languages could be defined), it is not generally acceptable to express a description
in multiple languages. The method can translate a parsed description into the language
of the query by processing a set of rules that is defined for the description scheme.
This set of rules effectively replaces the descriptors in the DesOM with equivalent
descriptors in the same language as the query. This method provides a controlled mapping
between descriptors in different languages rather than allowing a mapping to be estimated
by a translation ability in the search/query/filter engine.
[0106] Equivalences between non-textual and textual descriptions can be provided in a similar
manner. For example, if the colour of an object in an image is stored as a (R, G,
B) value then a rule could instantiate another descriptor in the DesOM that maps the
particular (R, G, B) values to particular colours expressed as a text string (eg.,
red, green, blue, orange, etc.).
[0107] The rules are stored as a rule set that can be specified as part of the description.
The extra or translated descriptors are not serialised and are only generated when
they are needed. In other words, they only exist in the DesOM and not in the XML document
that represents the description. Rule sets are a way of providing a richer, more flexible,
description at the time of the description being processed without increasing the
overhead of storing redundant information.
2.4.1.3 Association Relationships
[0108] Association relationships specify the context in which a defined Descriptor can occur.
The context includes relationships such as containment (eg., Descriptor A must occur
within a Descriptor B), sequence (eg., Descriptors A, B, and C must occur in that
order), and cardinality (eg., Descriptor B can occur only once in an instance of Descriptor
A).
[0109] To a large extent these association relationships can be specified in an XML DTD
using an element's content model. A content model is a simple grammar governing the
allowed types of child elements (ie., containment) and the order in which they are
allowed to appear. Group connectors [and (comma), or (vertical bar)] are used to specify
the order in which child elements can appear within the element. Occurrence indicators
[one or more (+), zero or more (*), or zero or one (?)] are used to specify the cardinality
or occurrence of the child elements in the element's content. Element content models
are described in Section 3.2.1 of 7]. The XML content model 1.0 does not allow a specific
non-zero cardinality to be defined (eg., an image can contain 0 to 20 objects) and
consequently this association property is not provided in the preferred DDF implementation.
2.4.1.4 Spatial, Temporal and Conceptual Relationships
[0110] Many descriptors will need to be able to model spatial, temporal and conceptual relationships
often in addition to association relationships. For example, a Region Adjacency Graph
which describes an image, comprises a graph object that contains a set of regions.
In addition to being part of the graph object, each region also has a set of neighbouring
regions (ie., spatial relationships). These relationships can be described using references
to the relevant descriptors in the description.
[0111] In the method, these relationships are represented as Descriptors having atomic Descriptor
values with IDREF or IDREFS data types. A set of core relationship descriptors is
defined in the DDF Core DTD to enable DesOM implementations to realise a greater extent
of semantic interpretation. Examples of the types of descriptor definition to are
included are provided in Section 3.1.3.
2.4.1.5 Navigational Relationships
[0112] Many applications may require that descriptors can be explicitly linked to spatially
and/or temporally localised extents in a resource. Although the resource is typically
that being described, this is not always the case. The links should enable navigation
from descriptors to indicated locations in a resource (eg.. from a descriptor to a
spatially and temporally localised extent in a digital video stream).
[0113] The means for expressing these links has been derived from an existing approach to
this problem, namely the HyTime standard, which uses location address elements, or
locators. This method requires that the resource must be declared as an external entity
in the description. Link elements are then declared to create contextual (having a
single linkend) and independent (having more than one linkend) links between locations
in the description and extents in the declared entity. Locators provide a means for
addressing extents in the resource being described.
[0114] The Locator and Extent elements defined in the DDF Core DTD are much simpler than
those specified in the HyTime standard as the latter provided more than was required
for the DDF requirement of linking. Also, because it is difficult to envisage all
the possible different forms of locators required for the different media types it
was believed that description scheme designers should not be limited in the scope
of their design of required locators.
2.4.2 Expression of Specific Data Types
[0115] The content model for an element can specify the order and cardinality of allowed
child elements (see Section 2.4.1.3), that the element has EMPTY or no content, that
the element has parsed character data (ie., #PCDATA), or some mixture of parsed character
data and child elements (ie., ANY). [The allowed content models of elements are detailed
in Section 3.2.1 of XML 1.0 WC3 recommendation]. If the content of an element is used
to store the representation value of a feature (eg., "DateCreated"), then the content
model of the relevant Descriptor would need to be "#PCDATA" (or "ANY") and the content
would be represented as a character string. Although this might be acceptable for
a textual interpretation of the description, this form of representation does not
permit more advanced queries where, for example, descriptions may be required to be
selected if the "DateCreated" feature has a representation value that is later than
some provided date. In other words, it is necessary to know how to parse the character
content of the Descriptor (ie., the Atomic Descriptor Value).
[0116] The serialisation syntax of the DDF provides data typing of an element's content
by using a
dataType attribute for the element. Although it would not be explicit for a Version 1.0 XML
(DOM) Processor, a DDF Processor can use the data type attribute to interpret an element's
content appropriately. Datatyping of element content has been considered as part of
the XML working group discussions and hence it would be preferable if the DDF could
remain consistent with the XML standard.
[0117] In addition to the basic data types (eg., integer, floating-point value, string,
date, time, etc.), the
dataType attribute should allow types such as ID, IDREF and ENTITY in order to enable Atomic
Descriptor Values to represent references to other Descriptors and links to entities
external to the description. The XML concept of ENTITIES is preferred to using a URI
data type in that the ENTITY type allows a URI to be linked to a type of the entity
(eg., JPEG image, Java class, etc.).
2.5 Implementation Issues
[0118] An implemented DDF Processor could use publicly available software (eg. IBM's XML
parser; to parse descriptions into a DOM structure and then the method transforms
this structure into a DesOM structure. The Java language is preferably used to implement
Descriptor Handler classes because of its cross-platform properties.
[0119] Actual implementations of a DDF Processor would not need to create a DOM as an intermediate
step and could parse the XML document directly into a DesOM structure using the DDF
description scheme. Such a processor would need to first interpret the subclassing
information in the DDF description scheme (see Fig. 2A).
[0120] A DDF Processor implementation could also take advantage of other core relationship
descriptors (see Section 2.4.1.4) to provide a richer semantic interpretation of descriptions.
Implementations could also interpret the linking elements when providing a graphical
representation of descriptions and incorporate rule-engines to process rules which
might be applied to to DesOM.
3. Serialisation Syntax Specification
3.1.1 Element Definitions
[0121] The preferred DDF includes the definition of a set of core elements using the XML/SGML
DTD syntax. This set, is preferably stored in a core, or set of core, DTDs. Appendix
A contains an example of such a DTD,
Core.ddf. Note that we use the extension "ddf" to differentiate this document from an XML
DTD which would typically have the extension "dtd". A DDF set of definitions needs
to have its subclassing/inheritance properties (eg., attribute inheritance from super
elements) processed before a description can be interpreted with respect to set of
DDF definitions. The set of core elements can be used as a basis for the definition
of application DTDs or description schemes. The element definitions in the
Core.ddf effectively provide a set of "foundation" elements from which description schemes
can be based.
[0122] This specification of the core element definitions for the proposed DDF is based
on Version 1.0 of the XML Specification. Elements that are included in the proposed
Core.ddf are named according to the naming conventions used for Java classes (ie., all words
in the name are capitalised and concatenated).
3.1.2 Core DDF Element Definitions
3.1.2.1 Descriptor Definition
[0123] The Descriptor element is the basic element which provides the data modelling properties
detailed in Section 2.2. Any clement definition requiring any of these properties
should be represented as a subclass of this element The element is the markup equivalent
of the object class of an object-oriented programming language.
[0124] The content model for the Descriptor element needs to allow for either parsed character
data (atomic representation value) or one or more Descriptor elements (compound representative
value). The content model of the Descriptor element is defined to be "ANY" so as to
allow the necessary content and be a valid XML DTD syntactical construct. However
in order to control content models more tightly, it is also possible to define two
subclasses of the Descriptor, the Atomic Descriptor and the Compound Descriptor. The
content models of these subclasses could then have the more restricted content models
of #PCDATA and (Descriptor+), respectively.
[0125] In specialisations of the basic Compound Descriptor element, the "Descriptor+" would
need to be interpreted by the DDF Interpreter as one or more Descriptor or subclasses
of Descriptor elements. Specialisations of the Descriptor element that use this content
model by default may have their content model extended to "ANY" during the DDF interpretation
process (see Section 2.4.1.1.3) in order to form a valid XML DTD for a description
scheme.

Attribute id
[0126] The value of this attribute provides a natural way to refer to a particular element
(eg., in references). It must be unique for the document.
Attribute xml:lang
[0127] The attribute
xml:lang is included in Version 1.0 of the XML Specification. It specifies the natural language
or formal language in which the content (of the clement) is written. The default language
used by the Descriptor element is English. If a description scheme was defined in
French, for example, then one approach would be to define a FrenchDescriptor in which
the value of
xml:lang was FIXED to "fr", and then derive all application descriptors from the FrenchDescriptor
element
Attribute dataType
[0128] Preferably, the definitions of many descriptors require some control over the data
type of an element's character data content.
[0129] The allowed data types for character data content are specified by the (XML) internal
parameter entity, DataTypes (see above). The
dataType attribute is only utilised if the content model for the Descriptor contains #PCDATA
and the provided content for the Descriptor contained character data. In other words,
if the content of a Descriptor is specified to contain child elements (ie., a compound
representative value) then the
dataType attribute is not used. In an alternative implementation, the allowable data types
could include a "Compound" type which would make the use of a compound descriptor
more explicit in its definition.
[0130] Character data content of a Descriptor is represented by a DDF Processor using a
AtomicDescriptorValue node (see Section 4.1.3 for the interface specification) rather
than a Text node as used by a DOM Processor.
[0131] The default value of the attribute
dataType is "String". This means that the
dataType attribute does not need to be included in a Descriptor element's definition if the
content of the element is to be treated as a string. Preferably, the DDF Processor
dates and times are based on the profile of ISO 8601. The types, ENTITY/ENTITIES/ID/IDREF
should be parsed as defined for the XML Version 1 standard.
[0132] Although the data type of the Descriptor element's character data content cannot
be directly used by XML version 1.0 and DOM version 1.0 specifications, it might in
some way assist textual access to the description. Also placing the data type of the
character data content in an attribute is consistent with many current proposals for
data typing in XML.
[0133] Some Descriptors will require their representative value to be limited to a list
of possible values (ie., an enumeration). In these cases, it is preferable to construct
Descriptor elements (having an EMPTY content model) for each of the enumerated values
and then specify the enumeration in the content model for the parent Descriptor. An
alternate approach is to include an enumeration data type and use a #PCDATA content
model.
Attribute superElement
[0134] The value of this attribute is an element name which is the parent (or super) element
of the Descriptor element. The parent elements definition must be available. Subclassing
is implemented as described in Section 2.4.1.1.
[0135] The information in this attribute is used by the DDF interpretation process (see
Fig. 2) to validate the defined subclassing and to process the inheritance of attributes.
When accessed at the DOM level, this attribute provides only descriptive information
about the immediate generalisation of the element. When processed at a DesOM level
the subclassing relationship(s) for the element are represented as a node list or
inheritance tree (see Section 4.1.1).
Attribute handler
[0136] The value of this attribute specifies an external entity for a Descriptor Handler
to be used to provide methods for the Descriptor element. The Descriptor Handler is
a class which contains methods that conform to a specified Descriptor Handler interface
(see Section 4.1.2).
[0137] The Descriptor Handler is specified using an ENTITY which can be defined in the description
scheme (preferably before the elements of the scheme are defined). The ENTITY declaration
can use a NOTATION to declare the type of the external entity and a helper application
required to process the ENTITY. In the example below, a NOTATION is declared for a
JavaClass type and this type is linked to the "Java" helper application (ie., Java
virtual machine). An individual Java class in then declared using an ENTITY declaration
which uses the JavaClass NOTATION.
〈!NOTATION JavaClass SYSTEM "Java"〉
〈!ENTITY MyDescHandler SYSTEM "MyDescHandler.class" NDATA JavaClass〉
[0138] Preferably, it is assumed that the methods provided by the Descriptor Handler do
not require any parameters that are not available from the DesOM (eg., resource from
a Description element). If methods of a Descriptor Handler require parameters to be
set from individual descriptions, then attributes of a specialisation of the Descriptor
element can be used to hold the parameter values. A Descriptor Handler could then
have a method to set the parameters from the attribute values in the DesOM.
3.1.2.2 Description Definition
[0139] A Description element is defined as a subclass of the Descriptor element. It represents
the root node of an instance of the DesOM and should be the root element of a serialised
description (ie., an XML document).
[0140] The content model for the element is defined as one or more Descriptors. This is
a restriction of the content model of the Descriptor element. As with the Descriptor
element, definitions of specialisations of this element need to be interpreted by
the DDF Interpreter as one or more Descriptor or Descriptor subclass elements.

Attribute superElement
[0141] Although the attribute
superElement is inherited from the Descriptor element's definition, it is redefined here to declare
that the Description element is a subclass of the Descriptor element. The default
superElement is declared as #FIXED so that instances of the Description element cannot
redefine the superElement value. Note, that a specialisation of the Description element
can further restrict this default attribute value by specifying an element name that
is a subclass of the Descriptor element (see 2.4.1.1.2). Attribute
resource
[0142] This value of this attribute should contain an entity which references the resource
being described by this description. The resource must have been declared as an entity
in the description before the Description can be declared. The resource type can be
obtained by using a NOTATION, defined in either the description scheme or in the
Core.ddf, to describe the type of entity.
   eg., 〈!NOTATION MPEG-2 SYSTEM "MPEG-2Player"〉.
[0143] The NOTATION can then be used by an external ENTITY declaration in the DOCTYPE declaration
of the description:
   eg., 〈!ENTITY MyVideo SYSTEM "MyVideo.mpg" NDATA MPEG-2〉.
[0144] Note, that this method of referencing the resource being described not only identifies
it as an MPEG-2 resource but also provides the name of a processor (helper application)
for the resource type.
Attribute dateResourceLastModified
[0145] The value of this attribute is a string representation of the date that the resource
was last modified. At any stage a process can check to see if this date has changed
(by string comparison), and update the description if necessary.
Attribute ruleSets
[0146] The value of this attribute contains one or more external ENTITIES. Each ENTITY refers
to an XML document that contains a set of rules that can be applied to the description
(see Section 7).
3.1.3 Descriptors Representing Spatial, Temporal and Conceptual Relationships
[0147] A set of Descriptor elements have been included to provide spatial, temporal and
conceptual relationships between descriptors. These elements are preferably a part
of the core DDF elements rather than specified in individual application description
schemes in order to improve the semantic interpretation of description. These relationship
Descriptor elements can have either atomic or compound representation values. The
element set below is included more by way of example rather than attempting to demonstrate
a complete list of the types of relationships that need to be modelled.


3.1.4 Elements Representing Navigational Relationships
[0148] The preferred DDF also includes some core elements that enable the linking of descriptions
to spatio-temporal extents of the content being described. A spatio-temporal extent
is defined to be a section of the content that is spatially and/or temporally localised.
For example, a spatio-temporal extent of a digital video signal might be represented
as a rectangular region that extends for a number of frames. A contextual link, CLink,
is defined to represent the common cross-reference or navigational link. A CLink connects
the location in the description where the link occurs to another location. In other
words, a CLink has a single linkend attribute. An independent lint, or ILink is also
defined for applications that require links connecting more than two locations or
stored separately from the link's location in the description. These elements are
defined as subclasses of the basic Descriptor element so that they are interpreted
by the DDF and represented as nodes in the DesOM. Since these elements do not require
any of the data modelling properties described in Section 2.2, there may be a case
for allowing elements, such as the set defined below, to not be based on the Descriptor
element but still interpreted by a DDF processor.
[0149] The definitions of these linking elements are included in
Core.ddf. Note it might be preferable to include the definition of the core spatio-temporal
linking elements in a separate (ddf) DTD.


[0150] The core Locator element simply provides an address for the location of one or more
Extent elements within a particular resource. The value of the
resource attribute identifies the resource using an ENTITY that has been previously declared
in the description. This requires that the
Core.ddf also includes a sufficiently rich set of NOTATIONS that include the types of resources
that are going to be referenced by entities (eg., JPEG, TIFF, MPEG-1, MPEG-2, etc.).
An instance of a Locator must contain one or more instances of an Extent. It is desirable
to specify the resource even if it is the same resource specified for the description.
[0151] Several subclasses of Extent elements are defined in the
Core.ddf. The definitions of these elements are included below. These element definitions
provide an example of the types of Locator and Extent elements that could be required.



4. DesOM API Specification
[0152] The DesOM interface extends the existing DOM Object Model (DOM) interface specification.
The DOM is a platform and language-neutral interface that will allow programs and
scripts to dynamically access and update the content, structure and style of XML and
HTML documents. It provides a standard set of objects for representing HTML and XML
documents, a standard model of how these objects can be combined, and a standard interface
for accessing and manipulating them. Vendors can support the DOM as an interface to
their proprietary data structures and APIs, and content authors can write to the standard
DOM interfaces rather than product-specific APIs, thus increasing interoperability
on the Web.
[0153] The DOM interface does not stipulate how its associated methods are to be implemented.
For, example, the method getElementsByTagName() (Appendix K) must satisfy the DOM
interface, but can be implemented in any manner as a developer so choses. The implementation
of the methods associated with DesOM and DOM interfaces are not essential to the invention
and will not be described further.
[0154] The DOM Level 1 Specification is now publicly available; it has been reviewed by
W3C Members and other interested parties and has been endorsed by the Director as
aW3C Recommendation. For further details on the DOM version 1.0 standard reference
is made to the W3C website HTTP://www.w3.org/TR/1998/REC-DOM-level-1-199810001.
[0155] As mentioned, the DesOM requires extensions to the DOM. These extensions are in the
form of additional interface specifications. These specifications are detailed in
this Section using the Object Management Group (OMG) Interface Definition Language
(IDL). The specified interface represents a minimal interface for the DesOM.
4.1.1 Interface Descriptor
[0156] The Descriptor node object in the DesOM is a subclass of the DOM Element node object
(see Appendix K). Like the Element node object, the Descriptor node object represents
both the Descriptor element, as well as any contained elements.
IDL Definition
[0157] 
Method setHandler()
[0158]
Set the DescriptorHandler for this Descriptor node object. This handler can be instantiated
on the basis of the handler ENTITY that is specified as the value of the handler attribute for the Descriptor element.
- Parameters
- handler
- The DescriptorHandler to be assigned to this Descriptor node.
- Returns
- void
- Exceptions
- This method throws no exceptions.
Method getHandler()
[0159]
Returns the DescriptorHandler for this Descriptor node object.
- Parameters
- None
- Returns
- DescriptorHandler for the Descriptor node object.
- Exceptions
- This method throws no exceptions.
Method getSuperElements()
[0160]
Returns a list of Descriptor generalisations or superElements for the Descriptor node
object.
- Parameters
- None
- Returns
- NodeIterator
- Exceptions
- This method throws no exceptions.
4.1.2 Interface DescriptorHandler
[0161] The DescriptorHandler object provides methods for a class of Descriptor nodes. A
DescriptorHandler can provide methods for more than one type of Descriptor. For example,
a collection of Descriptors might use the same similarity metric.
[0162] Preferably, the interface for the DescriptorHandler is fixed. In other embodiments
this interface can be specified either for a Descriptor or description scheme.
[0163] The methods of a DescriptorHandler are generally implemented as class (static) methods.
IDL Definition
[0164] 
Method canCreateDescriptorContent()
[0165]
Returns true if the DescriptorHandler contains an implemented method that can create
the content for a descriptor..
- Returns
- True if a method has been implemented else returns false.
Method createDescriptorContent()
[0166]
Generates the content (ie., child nodes) of the specified Descriptor node object using
the specified resource.
- Parameters
- descriptor
- The Descriptor node object for which the content (ie., child nodes) is to be created
from the resource.
- resource
- The resource, represented as an entity, from which the content is to be derived.
- Returns
- void
- Exceptions
- This method throws a ResourceNotFoundException if the resource could not be found,
or a IllegalResourceException if the resource is not compatible with the method.
Method removeDescriptorContent()
[0167]
Removes the content (ie., child nodes) of the specified Descriptor node. This method
might be invoked to reduce the complexity of a description for storage and would typically
only be invoked if the DescriptorHandler was capable of recreating the specified descriptor's
content.
- Parameters
- descriptor
- The Descriptor node object for which the content (ie., child nodes) is to be removed.
- Returns
- void
Method getSimilarity()
[0168]
Returns a similarity metric in the range of [0, 1.0] which provides a measure of the
similarity between the two specified Descriptor node objects.
- Parameters
- descriptor1
- The first of the two Descriptor node objects to be compared.
- descriptor2
- The second of the two Descriptor node objects to be compared.
- Returns
- double
- Exceptions
- This method throws an UnmatchedDescriptorException if the two Descriptor node objects
are of incompatible types.
4.1.3 Interface AtomicDescriptorValue
[0169] The AtomicDescriptorNode object is a subclass of the Text (node) object that is specified
as part of the DOM [The Text object contains the non-markup content of an Element].
It provides additional methods to the Text object which interpret the string data
content of the Text object as other data types (ie., it is effectively a typed text
node). The data types available are as specified for the
dataType attribute of the Descriptor element (see Section 3.1.2,1). It is assumed in this
specification that the XML data types (ie., IDs, IDREFs, ENTITY, ENTITIES) would be
interpreted from the string value of the AtomicDescriptorValue node.
[0170] Dates and times are represented using the date an time formats specified by the profile
of ISO 8601. Implementations of the AtomicDescriptorValue object can provide further
methods that provide extra date functions (eg., getDataAsDateYear(), getDataAsDateMonth(),etc.).
IDL Definition
[0171] 
Method getDataAsInt()
[0172]
Returns the value of the Text node as an integer.
- Parameters
- None I
- Returns
- Integer
- Exceptions
- This method throws a DDFDataFormatException if the character string could not be parsed
as an integer.
Method getDataAsFloat()
[0173]
Returns the value of the Text node as a float value.
- Parameters
- None
- Returns
- Float
- Exceptions
- This method throws a DDFDataFormatException if the character string could not be parsed
as a float value.
Method getDataAsDouble()
[0174]
Returns the value of the Text node as a double value
- Parameters
- None
- Returns
- Double
- Exceptions
- This method throws a DDFDataFormatException if the character string could not be parsed
as a double value.
Method getDataAsDate()
[0175]
Returns the value of the Text node as an ISO 8601 date
- Parameters
- None
- Returns
- ISO 8601 date
- Exceptions
- This method throws a DDFDataFormatException if the character string could not be parsed
as an ISO 8601 date.
Method getDataAsTime()
[0176]
Returns the value of the Text node as an ISO 8601 time.
- Parameters
- None
- Returns
- ISO 8601 time
- Exceptions
- This method throws a DDFDataFormatException if the character string could not be parsed
as an ISO 8601 time.
5. Example of a Description Scheme
[0177] An example of a description scheme expressed in DDF is contained in Appendix B. The
description scheme aims to provide a description for digital video footage of an Australian
Football League (AFL) game. This description scheme makes use of some core element
definitions that are contained in Appendix A. The Core.ddf is declared as an internal
parameter entity B1 and then included in the description scheme using the % operator
(see B2). The indicated lines B1 and B2 of the description scheme result in all the
element definitions included in Appendix A being available to the example description
scheme.
[0178] In the definition of the descriptor AFLGameDescription B3 a descriptor handler B4
is specified. In this example, the descriptor handler is implemented as a Java class
(AFLGam)Gen.class in the example contained in Appendix B3) having a predetermined
procedural method which automatically generates the (description) content for the
AFLGameDescription descriptor by analysing the digital video signal containing the
footage of the game being described.
[0179] It should be noted that although the AFLGameDescription element is defined as a specialisation
of a Description element, a Description element is just a specialisation of a Descriptor
element, and so the AFLGameDescription can also be treated as a Descriptor.
[0180] An example description generated from the description scheme contained in Appendix
B is shown in Appendix C. This example description would typically have been initially
generated by the descriptor handler for the AFLGameDescription descriptor, however
manual creation is also possible if an annotator so desires. The procedural method
to generate the content for the descriptor AFLGameDescription would typically analyse
the digital video resource signal containing the footage of the game to be described,
identify the start and end of the four quarters of play, and within each quarter track
and, if possible, identify individual tracked players. The tracking could be achieved
using motion analysis of the digital video resource with player identification being
achieved by attempting to recognise a player's number from his/her jersey. It is not
an object of this invention to specify a method for generating the content of the
description.
[0181] Clearly it is unlikely that all the information required for the description, as
specified by the description scheme, could be automatically generated from an analysis
of the digital video resource signal. Where information is not available (eg., date
and location of the game), the content generation method can either generate empty
descriptors or simply omit the descriptors from the description. At a later date an
annotator can add this information manually if it is required. Similarly, it might
be too difficult for an automatic analysis to classify the action of each tracked
player. For example, it might be difficult to automatically analyse whether the player
was involved in a mark, a kick or a tackle. This information could also be provided
at a later date. In fact, an annotator could use a Digital Video Browser System, as
described in Section 13, to browse the digital video resource and annotate as required.
On completion of annotation the Digital Video Browser System could also be used to
select to play all those sections of the digital video resource in which a particular
player was involved, or all those sections in which a mark occurred. In other words,
the Digital Video Browser System could be used to complete any annotation tasks and
browse the described digital video resource.
[0182] Another example of a method to create the content for a descriptor, is one where
the resource to be described has already been described using another description
scheme. For example, a digital video camera might generate a description (using, for
example, a Video Capture Description Scheme) for a digital video resource as it is
being captured. The automatically generated description might contain information
such as exposure, focus, eye-gaze location, shot boundaries, etc. It might be desirable
to maintain some, if not all, of the information automatically recorded using the
source description scheme, however it might be preferable to describe the digital
video resource using another more generally accepted description scheme, in this ease
the destination description scheme. In this case the descriptor handler(s) in the
destination description scheme could provide a mapping of descriptors from the source
to destination descriptions. This mapping would typically be provided in the content
creation method of descriptor handler for the Description element of the destination
description scheme. This transformation from one description scheme to another could
also be achieved by applying rules to the DesOM (see Section 7).
6. Methods of Applying Procedures.
6.1 Method of Generating Descriptions of Electronically-Accessible Resources
[0183] Turning now to Fig. 7A, there is a shown a method of generating descriptions of an
electronically accessible resource. The method commences at step 700A and continues
at step 702A where a description scheme is read by a processor (i.e. the description
generator). In the next step 704A, a processor identifies the one or more DescriptorHandlers
in the description scheme and afterwards the method continues to step 706A. In step
706A, the processor identifies the procedures corresponding to the previously identified
DescriptorHandlers. These procedures are in the form of procedural code contained
in the DescriptorHandlers. In the next step 708A the procedures are applied to the
resource. The procedure generates a representative value which is associated with
an attribute (i.e. feature) of the resource. The method then outputs at step 710A
the results of the application of the procedures. The method terminates at step 712A.
Preferably, these procedures result in the automatic generation of a description of
the resource in the form of a DesOM which may be subsequently serialised as a XML
document. However other procedures or processes may be envisaged. Further this resultant
description is preferably interpretable by both humans and machines.
6.2 Methods of Applying Procedures to a Description
[0184] Turning now to Fig. 7B, there is shown a flow diagram of a method of applying procedures
to description(s) of resource(s). The method commences at step 700B and continues
at step 702B where a description is parsed by a DDF processor. In the next step 704B,
the DDF processor identifies within the associated description scheme one or more
DescriptorHandlers. In the next step 706B of the method, the DFF processor identifies
the one or more procedures associated with the previously identified DescriptorHandlers.
These procedures are in the form of procedural code contained in the DescriptorHandlers.
In the next step 708B the procedures are applied to the DesOM corresponding to the
description. The method then outputs at step 710B the results of the application of
the procedures. The method terminates at step 712B. The method envisages many different
types of procedures that can used in the method. In one embodiment, the method computes
the similarity between two descriptors of the same type. In this embodiment, the descriptions
are parsed by the DDF processor and a common descriptor definition is identified by
the processor. The DDF processor then identifies within the description scheme containing
the common descriptor definition an associated DescriptorHandler which contains procedural
code for computing similarity between two descriptors. The method then applies the
procedural code to the DesOMs associated with the descriptions and determines the
similarity of the descriptors and hence the similarity of the two resources. The method
then outputs the results of the similarity computation. This embodiment has particular
application in searching/querying descriptions of resources. In another embodiment,
the procedural code of the method can encode and/or decode one or more descriptor
components of the description of a resource. This embodiment has particular application
for efficient and/or secure transport or storage of descriptor components of descriptions
of resources.
6.3 Examples of Methods of Generating Descriptions and Applying Procedures to Descriptions
[0185] The method of generating descriptions and applying procedures standardises the way
descriptors and description schemes are defined. These descriptors and description
schemes can be used to describe various types of multimedia information. Using the
descriptors and description schemes, descriptions that allow fast and efficient searching
can be created and associated with multimedia content. The preferred embodiment provides
for automatic extraction of descriptors. However, in general, this is only possible
for low-level features. Features that represent higher level of abstraction usually
have to be set manually or, at least, semi-automatically.
[0186] The method also provides a standard mechanism for associating descriptors with procedural
code that generate them, which can greatly facilitate the deployment of the description
schemes. For instance, such association will allow the development of very general
applications such as a multimedia database server, that make use of the procedural
code to generate descriptors for new descriptions or for comparing descriptions. Apart
from procedures for generating descriptors, procedures for validating descriptors,
computing the similarity between two descriptors of the same type as well as encoding
and decoding descriptors can be made available to applications through a standard
interface.
[0187] For example, the following exemplary applications are possible utilising such procedural
code. One can
- whistle a melody to find a song,
- play a few notes on a keyboard and get in return a list of musical pieces,
- draw a few lines on a screen and get in return a set of images containing similar
graphics, logos, ideograms,
- define objects, including colour patches or textures and get in return examples,
- using an excerpt of Pavarotti's voice, and getting a list of Pavarotti's record, etc.
[0188] The above scenarios involve the user providing some example content with his/her
query. Standardisation of description schemes (in addition to a language for the exposure
of DSS) would facilitate querying over multiple remote multimedia databases.
[0189] There a number of problems relating to the standardisation of descriptors and description
schemes. For example, there is a problem with even the relatively simple colour histogram
descriptor. Even if two description providers use the same colour histogram descriptor,
they might use it in a different manner such as using different quantisation. This
will mean that histogram bin
i may mean different things to different description providers. When one uses the histogram
of an image as an example to search multiple image databases, one either has to compare
and/or convert between different histograms. Both of these alternatives are difficult
to achieve and error prone. It is also not practical to have every database server
to re-compute the histogram of its images in the same way the example histogram was
generated.
[0190] The inventors propose two possible approaches for standardisation of description
schemes:
1. Standardise completely, to the last detail, the colour space, the colour quantisation
(bins) for colour histograms, and consequently the matrix of cross-bin similarities.
2. Use the image itself as the example. Then, each database uses its own extraction
method to compute the histogram of the received query image and then compare the histogram
with the rest of its database.
[0191] The first option is not very practical, as people will never agree with every detail
of the histogram's specification. Option 2 is more practical and cleaner, for histogram
and most of other image queries. Option 2 means that each database can use their own
particular parameters for descriptors and also their own methods of computing similarity
between descriptions.
[0192] Only a low-level descriptor - the colour histogram - that could be generated from
the content was considered as an example in these approaches. In practice, the query
might also contain textual description or keywords that the user input which can be
mapped to some high-level descriptors such as the photographer's name,) the caption
of the image, etc.
[0193] As described previously, a base Descriptor class from which all descriptors and descriptions
are to be based is defined and a description is treated as a compound descriptor.
The base Descriptor class includes an attribute that allows the URI of a handler that
implements the descriptor's procedures to be stored. It provides a standard mechanism
for associating descriptors with procedural code. The handler is called a descriptor
handler. A standard API (application program interface) for the descriptor handler
is based on a DescriptorHandler class. The DescriptorHandler provides methods for
generating the content (or value) of the descriptor, createDescriptorContent(), and
computing similarity between two descriptors of the same type, getSimilarity(), (see
section 4).
[0194] An alternative embodiment of the DesOM interface is now described below. The detailed
definitions of the DesOm interface of the DescriptorHandler class can be found in
Code Definitions A. In short, the DesOM interface of the DescriptorHandler class specifies
the following methods;

[0195] In addition, the Descriptor class provides the following methods:

[0196] Different descriptor handlers can be implemented (usually by different developers)
for any descriptor with different trade-offs among performance, functionality and
complexity. However, all descriptor handlers of a descriptor must comply with the
definition of the descriptor. That is, the descriptor handlers can only generate descriptor
value that conforms to the definition of the descriptor. At the tame time, the descriptor
handler can assume that any input descriptor will conform to the definition of the
descriptor.
[0197] A descriptor designer may assign a default descriptor handler to a descriptor. However,
a user of the descriptor is free to choose another handler or none at all.
[0198] Not all descriptors are required to have a descriptor handler. Indeed, many descriptors
of higher level of abstraction are expected to be handler-less. Nevertheless, even
low-level descriptors may not have a handler. For instance, while a handler may exist
for a histogram descriptor, we don't expect a handler would be required for a descriptor
that holds the creation date of a document.
[0199] Even if a descriptor has a descriptor handler, a description is not required to use
or reference the handler. In addition, different instances of the same descriptor
class may refer to different descriptor handlers. For instance, due to the different
characteristics of different classes of images, for each class of image a different
handler with a more efficient segmentation algorithm is used for creating its region
descriptors. Moreover, applications are not restricted or required to use the descriptor
handler referred to by a descriptor instance.
[0200] At the same time, not all descriptor handlers (which are subclasses of the DescriptorHandler
class) will override the default implementation of all the methods of the base DescriptionHandler
class, that is, provide support for all methods of the base class. For instance, a
validation method may be implemented to check that an ISBN has the right format; however,
no method is implemented to generate the ISBN. Another example is that while a descriptor
handler may support the getSimilarity() method of a certain descriptor for an non-electronically
accessible resource, it would not support the corresponding createDescriptorContent()
method.
[0202] The data (value) of a descriptor (or feature) usually depends on some parameters.
For instance, the data of the colour histogram will depend on the colour space used
and the quantisation. These parameters, in general, are also used by the corresponding
descriptor handler if one exists. Methods are provided in the DescriptorHandler interface
for obtaining a list of relevant parameters and setting the value of the parameters.
Note that the settings of the parameters control the characteristics of a descriptor
instance but are not related to the actual content the descriptor instance described.
[0203] In the light of the fact that the DDF is XML based, the parameters are specified
as XML attributes and data (value) describing the resource (content) should be part
of the content model. For instance, an instance of the colour histogram descriptor
may look like:


[0204] The bin size, which is a parameter of the histogram, and the starting rgb value of
each bin, which are parameters of the (frequency) bin, are specified as XML attributes.
In contrast, the bin frequency, which describes the number of occurrence of a range
of rgb value in the content, appears as value of the content model. Nevertheless,
the principle of using XML attributes for descriptor parameters can only be treated
as a guideline for good descriptor design and cannot be verified by a DDF processor.
[0205] As is evident from the interface defined for the DescriptorHandler class, a descriptor
handler may be used in the automatic creation of low-level descriptions, generate
example descriptors for searching database, computing similarity between descriptors
of the same class, validating descriptor content, and encoding and decoding descriptor
content.
[0206] Many low-level descriptors can be and, indeed, are expected to be extracted from
the content automatically. It is even expected that some low-level descriptors can
be created real time as the content is being captured. For instance, during the recording
of a video or in subsequent processing, a descriptor handler for some generic video
segment description scheme can use the metadata provided by the video camera to segment
the video temporally into clips (segments) and generate a description describing the
structure of the video. Note that descriptor handlers of a non-standardised description
scheme could also be used. For example, Fig. 8 shows a video processing application
808 generating a video segment description 802 utilising video and camera meta data
804. The video processing application 808 uses a video segment descriptor handier
800 from a standard library 806 in generating the description 802. As can be seen,
the description 802 refers to the descriptor handler 800.
[0207] When generating the description, the processing application calls the following methods
of the descriptor handler:
the getParameters() method to get the list of relevant parameters,
the setParameterValue() method to set the parameters required, and
the createDescriptorContent() method to generate the descriptor.
[0208] If required, the application may call the getXML() method of the descriptor to get
the XML serialisation of the descriptor node. It is expected that other structural
components of the video that are difficult to extract automatically and higher level
descriptors that describe the semantics of the structural components would added to
the description later with the aid of interactive tools.
[0209] The descriptor handler approach also allows developers to develop different extraction
algorithms for generating descriptions for (low-level) features, and market or distribute
them as some sort of "plug-ins".
[0210] Individual database servers can use the same set of descriptor handlers referred
to by the descriptions it stored to generate similar or compatible descriptors for
any example object specified in the query. A database server can then use the descriptor
handlers' getSimilarity() method to compare the descriptors of the example object
with those of the stored descriptions. For instance, in the above option 2, the client
can send an example image with its query to multiple remote image databases. Each
database will then generate a histogram descriptor of the image using the descriptor
handler referred to by the descriptions of its images and the same parameter settings
used by the descriptions of its images.
[0211] For example, Fig. 9 shows how descriptor handlers can be used to support query-by-example
searches over multiple remote image databases. A client 900 sends an example image
902 with its query to description/content providers A to Z. Each description/content
provider A to Z comprises a image database 904 for storing images, a description database
906 for storing colour histograms of the stored images, and a database search engine
908. The description/content provider A, upon receipt of the query, generates 910A
a corresponding histogram descriptor 911A utilising the colour histogram handler 912A
referred to by the image colour histograms 914A stored in its description database
906. The description/ content providers B to Z generate corresponding histogram descriptors
911B,...,911Z in a similar manner. Namely, each provider generates a histogram descriptor
of the example image using the descriptor handler referred to by the descriptions
of its images and the same parameter settings used by its descriptions. The provider
A then computes the similarity of the example histogram 911A with the image colour
histograms 914A stored in its description database 906. The providers B to Z compute
the similarity of the example histograms 911B,...911Z with the corresponding image
colour histograms 914B,...,914Z in a similar manner. Those images and/or descriptions
having a similar colour histogram are then retrieved from the databases 904, 906 and
are transmitted by the providers A,...,Z as query results to the client 900. In this
way, each provider may use different procedures for generating colour histograms,
but at the same time provide consistent query results. The descriptor handler approach
also allows a single database to use histograms with different parameters for the
different classes of images it stores.
[0212] Descriptor handlers also provide a flexible mechanism for computing similarities
between two descriptors of the same class. The simple interface of the getSimilarity()
method hides the complexity in computing the similarity between two descriptors. It
allows the use of an appropriate algorithm and similarity metric for each class of
descriptor and takes into account the different parameters the descriptors used (such
as the different bin sizes used by two rgb histograms).
[0213] The descriptor handler also provides a way of validating descriptor content, It is
possible in the serialisation syntax of the DDF (or an equivalent description definition
language) to support to declaration of constraints. However, such a declarative approach
is only possible for simple constraints such as such as maximum value, minimum value,
etc. Alternatively, the serialisation syntax can support the use of an object model
such as DOM and script language such as ECMAScript for specifying complex constraints.
However, procedural code is generally a more efficient way for validating complex
constraints.
[0214] Descriptor handlers also allow a more flexible approach for encoding and decoding
descriptions or particular descriptors in descriptions. Instead of using a single
encoding/decoding algorithm for the entire description, more efficient encoding/decoding
mechanisms can be developed for individual descriptors that make use of the characteristics
of the individual descriptor. These mechanisms could be made available through the
encode()/decode() method of descriptor handlers. The encoding/decoding procedure of
any standardised descriptor and description schemes can be made available as methods
of some descriptor handler library.
[0215] Fig. 10 shows an example how descriptor handlers might be used for encoding/decoding
standardised descriptors. The processing applications 1004, 1006 of the description
consumer A and description provider B make use of methods of the descriptor handlers
1002 of a standard library 1000 to decode 1010 and encode 1008 (as well in the case
of the provider) the descriptor instance 1012.
[0216] The basic methods of the descriptor handler can be divided into two types: one that
requires the resource (the content to be described) to be accessible, and the other
that doesn't. Only the createDescriptorContent() belongs to the first type and requires
the content as well as some packages for processing the content to be available. The
other methods such as GetSimilarity(), validate(), encode() and decode() only operate
on descriptor instances and do not require the use of a special multimedia (handler)
library.
[0217] In addition to it being inefficient to upload content to a remote site for description
generation, security and privacy issues with regard to the content exist. Therefore,
it is expected most descriptions will be generated locally on sites where the content
is located. Even in the case depicted in section 3.2, each database server uses a
local descriptor handler to generate descriptors for the query example. In the case
where content is downloaded for description generation, the application will still
be using a local descriptor handler. Hence, as far as description generation is concerned,
any descriptor handler used would be a local one.
[0218] Java presents an ideal object-oriented language for implementing descriptor handlers
because of its cross-platform properties, its growing support on a large variety of
devices of various sizes and its close tie to the Web through which most descriptions
are expected to be delivered. Some concern has been expressed over the issues that
Java applications are not as efficient as other compiled code and that most existing
features extraction algorithms are not implemented in Java. The advent of Just-In-Time
(JIT) compiler has greatly improved the performance of Java applications and applets.
In addition, descriptions are likely to be generated using local descriptor handlers.
That is, the createDescriptorContent() method is typically invoked locally. Hence,
it is free to use any locally installed multimedia library including non-Java library
through the Java Native Interface. As for the other methods of the descriptor handlers,
they deal with descriptions and not content. They are usually not as processing-intensive
as the createDescriptorContent() method. Standard Java packages are usually sufficient
for their purposes. Hence, they can have a pure Java implementation which remote sites
can download for execution. Signed applets can be used to lift the severe constraints
that are typically imposed on standard applets. For instance, an appropriately signed
descriptor handler may be allowed to write to and read from a specific local directory.
[0219] Fig. 11 shows an example of descriptor handlers implemented as Java applets. The
content/description provider B comprises a content database 1102, a description database
1104, a description generator 1112 and a description server 1110. Descriptor handlers
1116 of standardised descriptors are included in a standard library 1106 while those
of non-standardised descriptors 1114 are be available in other descriptor handler
libraries 1108. The descriptor handlers of both libraries 1108 and 1116 are implemented
in Java. The descriptions stored on the description database 1104 can be generated
by invoking the standard and/or non-standard createDescriptorContent() methods from
the other descriptor handler libraries 1108 (non-standard) and/or standard library
1106. The description server 1110 retrieves requested descriptions from the description
database 1104 and transmits them to the client A Before transmitting the descriptions,
the description server 1110 may invoke encoding methods from the standard and/or non-standard
libraries 1106, 1108.
[0220] The content consumer A comprises a processing application 1150 and a standard library
1152. The processing application 1150 receives the encoded description and is decoded
by invoking a decoding method from the standard library 1152. The decoded description
forms a descriptor instance. Non-standard descriptor handler applets 1114 could be
downloaded from the provider A, if required, and all their methods could be executed
on the client machine A. In particular, a non-standard decoding descriptor handler
can be downloaded 1154 to form a descriptor handler instance 1156. The processing
application 1150 then invokes the non-standard decoding descriptor handler 1156 to
decode 1160 the encoded description 1199 to produde the descriptor instance 1158.
[0221] The content/description provider B can use a Java Native Interface 1120 as part of
the Java packages and non-Java libraries 1122 of descriptor handlers. For instance
the createDescriptorContent() may be implemented in Non-Java code and thus can only
be invoked locally on the server machine B through the Java Native Interface 1120.
[0222] In summary, descriptor handlers could be implemented as applets. Descriptor handlers
of the standardised descriptors can be provided as part of a standard library (together
with the definitions of the standardised descriptors and description schemes). However,
users are free to use any valid descriptor handlers. Descriptor handlers for non-standardised
descriptors would be available separately in other libraries. It is proposed that
descriptor handler applets are properly signed and all methods of the DescriptorHandler
interface except possibly createDescriptorContent() are expected to be downloadable
to remote site for execution. The createDescriptorContent() method may require that
special libraries or native libraries would cause exception when not invoked locally.
7. Rule-based Processing using the DesOM
[0223] The internal memory structure of a description (ie.,. the DesOM) provides a convenient
structure on which to perform further processing of a description (or indeed the relevant
description scheme). This further processing can be achieved by locating patterns
of nodes in the DesOM and performing specified actions in response to the located
patterns. Each pattern-action association can be represented by a rule and a set of
related rules can be collected into a rule set.
[0224] Rules can be used to used to automatically create further descriptors based on existing
descriptors (see Section
8. Method of Extending Descriptions of Resources), to provide presentation properties for descriptions and description schemes (see
Section
9.
Method of Presenting Descriptions of Resources), and to represent queries (see Section
10. Method of Selecting Resource Descriptions). Rules can also be used to translate a description to the language of the query
(see Section
11. Method of Translating a Description of a Resource). The Digital Video Browser System described in Section 13 uses a method for formulating
rules common for each of these functions. This method is described below.
[0225] Each rule consists of a pattern (of nodes in the DesOM) and an associated one or
more actions. For each of the different functions (inference, equivalence, presentation
and selection), a different set of actions is often applicable. However each of these
functions can be enabled using a common rule grammar which will be described in this
section. The rule grammar can be defined in an XML DTD. The rules for the different
functions can simply use the common rule grammar (this is the case for the Digital
Video Browser System), or alternatively the allowable actions can be controlled by
defining different DTDs for each of the different functions (eg., an InferenceRules.dtd,
a PresentationRules.dtd, etc.).
[0226] Rules can be represented as, or in a manner similar to, Extensible Style Language
(XSL) rules. In the Digital Video Browser System (see Section 13), we have used the
following basic rule grammar.
Rules.dtd
[0227] 

[0228] Each Rule element has a target attribute that has a default value of "Element" and
a character string pattern attribute. The target attribute refers to the target of
the defined Rule. Typically inference, equivalence and search rules are targeted at
elements because the action of the rule results in either a new descriptor in the
description or the selection of a descriptor for a query. Presentation rules, however
are typically targeted at element definitions as their associated actions specify
how a particular descriptor type is to be presented in an application. A set of rules
can be serialised in an XML document. This is typically the case with inference, equivalence
and presentation rules, but may not be required for selection rules which may often
be processed on a single rule basis.
[0229] The role of the pattern character data string is to identify the particular elements
(or element definitions) to which the action is applied. This character string can
identify more than one element and can include element ancestry and attribute qualifiers.
Preferably, the pattern string is parsed according to the following Extended Backus-Naur
Form (EBNF) notation.
Pattern |
::=ElementPatterns(ConnectorOpElementPatterns)* |
ElementPatterns |
::=ElementPattern (AncestryOp ElementPattern)* |
ConnectorOp |
::= '|' | '&' |
AncestryOp |
::= '/' | '//' |
[0230] Each pattern can consist of one or more alternative patterns (ie., '|' represents
an alternative) or must satisfy more than one ElementPattern (ie. '&' connector operation).
Element ancestry is represented within a pattern by using the parent operator '/'.
Two patterns separated by a parent operator match an element if the right hand side
matches the element and the left hand side matches the parent of the element. For
example, the following Shot elements that have a Scene element as a parent and a VideoClipDescription
element as a grandparent match the following Rule's pattern:
〈Rule pattern = "VideoClipDescription/Scene/Shot"〉
〈Action〉 etc...〈/Action〉
〈/Rule〉
[0231] Two patterns separated by the ancestry operator '//' match an element if the right-hand
side that matches the element has at least one ancestor that the left-hand side matches.
So, for example, any Shot elements that have a VideoClipDescription as an ancestor
element will match the following Rule's pattern:
〈Rule pattern = "VideoClipDescription//Shot"〉
〈Action〉 etc...〈/Action〉
〈/Rule〉

[0232] An element within the pattern hierarchy may have qualifiers applied to it, which
further constrain which elements match the term. These qualifiers may constrain the
element to have certain attributes or sub-elements or may constrain its position with
respect to its siblings. The qualifiers are specified in square brackets following
the ElementTypeName (which is it tag name defined in the DTD). A pattern matches only
if all of the qualifiers are satisfied.
[0233] For example
1 any Shot elements that have a child element KeyFrame will match the following Rule's
pattern:
〈Rule pattern = "Shot[KeyFrame]"〉
〈Action〉 etc...〈/Action〉
〈/Rule〉
[0234] Attributes on the target element or any of its ancestor elements can also be used
to determine whether a particular rule applies to an clement. An attribute qualifier
can constrain an element to have either a specific attribute with a specific value,
or to have a specific attribute with any value. For example, the following pattern
matches a Bin descriptor which has as its parent a Histogram descriptor which has
an attribute noBins with a value of '100':
〈Rule pattern = "Histogram[attribute(noBins)='100']/Bin"〉
〈Action〉 etc...〈/Action〉
〈/Rule〉
[0235] Positional qualifiers can also be used to further constrain the pattern to match
on the clement's position or uniqueness amongst its siblings. For example, the following
example matches Object descriptors which are the only Objects in a KeyFrame descriptor:
〈Rule pattern = "KeyFrame/Object[OnlyOfType()]"〉
〈Action〉 etc...〈/Action〉
〈/Rule〉
[0236] The above description of the matching method permits pattern matching only on elements
(which are typically descriptors in the DesOM) or element definitions. Clearly there
are many possible embodiments for defining the syntax of the node pattern matching
without departing from the spirit and scope of the invention.
[0237] Each Rule can have one or more associated Action elements. In the Digital Video Browser
System (see Section 13) the allowable Action elements for rules has been limited to
the addition and removal of elements and attributes from elements (ie., descriptors)
in descriptions and the addition and removal of attribute definitions from element
definitions in a description scheme. The actions involving individual descriptions
are generally used by inference, equivalence and selection rules (see Sections 8 and
10) and the actions involving description schemes are generally used by presentation
rules (see Section 9).
[0238] The attributes of the Action elements, AddAttribute and RemoveAttribute, specify
the attribute to be added or removed from a target element (ie., an element that has
matched the specified pattern in the rule). The content of the AddElement action contains
the element to be added to the DesOM as a relation of a target element. The position
attribute of the AddElement element specifies where the new element should be added
with respect to the target element. This position attribute can indicate that the
new element is to be added as a sibling node before the target element (SiblingBefore),
as a sibling node after the target element (SiblingAfter), as the first child of the
target element (AsFirstChild), or as the last child of the target element (AsLastChild).
Clearly, since the element to be added to the DesOM is represented as parsed character
data (#PCDATA), an element hierarchy can also be added to the DesOM. The RemoveElement
action will simply remove a target element. Any child elements of the target element
will also be removed.
[0239] The AddAttributeDef and RemoveAttributeDef actions are only valid if the target for
the rule is an element definition. These actions are typically used by presentation
rules (see Section 9). The AddAttributeDef action uses the attName, attType and attDefault
attributes to specify the required information for the attribute definition to be
added to an element definition. The RemoveAttributeDef action will simply remove the
attribute definition that is identified by the value of the attName attribute of the
action. Attribute definitions can be replaced by including both an AddAttributeDef
and a RemoveAttributeDef action in a particular rule.
[0240] The Select action is typically only used by selection rules and is described in detail
Section 10. Rules can also be used to transform a description. These rules are used
to generate a second description conforming with a second description scheme.
8. Method of Extending Descriptions of Resources
[0241] Given a description scheme, it is possible that further descriptors can be automatically
created by inference or a known equivalence in a description based on the existence
or otherwise of a particular set of descriptors. For example, if a descriptor for
a digitally captured image representing light exposure levels indicated outdoor lighting
levels, then an additional descriptor could be automatically created to classify the
image as an "Outdoor Scene". Since the latter classification can be inferred from
the recorded light exposure levels there is no advantage in storing the classification
because it can always be re-generated while the inference rule exists. Rules can also
be used to generate textual descriptors based on non-textual descriptors or vice versa.
For example, the colour of an object might be stored in a description as a (R, G,
B) value. A rule could be formulated which maps each (R, G, B) value to one of a possible
number of colours represented in a text string (eg., red, green, purple, etc.). The
additional descriptors generated by inference or equivalence rules can result in a
richer description that can be exploited by applications (eg., search engines, filter
agents, etc.).
[0242] A set of rules that is applicable for a given description scheme can be serialised
(stored) in an XML document. In the Digital Video Browser System (see Section 13)
, a reference to such an XML document is stored in the value of the ruleSets attribute
of the Description element for the description scheme (see Section
3.1.2.2 Description Definition). It is possible to associate more than one rule set with a description scheme. In
the Digital Video Browser System ( see Section 13), if more than one rule set is specified
then it is assumed that both rule sets can be applied (ie., the individual rule sets
do not contain unresolvable rules). In other words, the individual rule sets are simply
combined and treated as a single rule set, in which the order of rules to be processed
is provided by the order of the listing of the individual rule sets and the order
of the individual rules within each given rule set. Inference and equivalence rule
sets can also be stored with an application without departing from the essence of
the invention, however in this event the value of the rules is limited to the particular
application.
[0243] Preferably, the Action elements typically used are the addition and removal of attributes
and elements from the DesOM. Replacement can be achieved by using a removal followed
by an addition Action element.
[0244] A set of inference rules is preferably invoked whenever a description is first processed
into the DesOM. The rules are iteratively processed until no further changes can be
made to the DesOM as some rules may depend on the actions of other rules. The rule
set may need to be (iteratively) reapplied whenever the description is updated (eg.,
a manual annotation in an application utilising the description). In the event that
an application has permitted changes to be made to the description, then before serialising
the altered description each change needs to be considered in light of the inference
rules in order to ascertain whether the descriptor can be inferred from a knowledge
of the other descriptors in the description. If a descriptor can be inferred then
it is excluded from the serialised description.
[0245] The method preferably associates a set of inference and/or equivalence rules to a
description scheme. This set of rules can be implemented according to the abovementioned
description and results in a richer description structure without any additional storage
or transport overhead which would result if the extra (inferred or equivalent) descriptors
were included as part of the individual descriptions. Being able to represent this
inferred or equivalent information as a set of rules that can be invoked when required
represents a significant saving in storage and transport cost if a large digital library
were to be described. In other words it can eliminate the storage and processing costs
of redundant information.
[0246] An important aspect of the method is that unlike existing stylesheet languages such
as XSL, the inference and equivalence rules do not form the basis of a construction
of a new tree structure which is typically used for rendering. In the method the rules
are applied to the memory structure that represents the description (ie, the DesOM)
and result in changes to that structure. The role of the rules is to provide a richer
description of the resource that can be exploited by applications (eg., search engines,
filter agents, etc.). This richer description does not necessarily need to be serialised
because the richer description can always be generated from the original description
using the rules.
[0247] The embodiment for applying the inference and equivalence rules has a limited set
of actions that can be performed on the selected elements (see Rules.dtd in Sectio
n 7. Rule-based Processing using the DesOM. This set of actions is sufficient for the Digital Video Browser System described
in Section 13, however it is possible that a more extensive set of rules may be required
for other applications.
[0248] Turning now to Fig. 12, there is shown a flow diagram of a method of extending a
description of a resource. In step 1200, the method commences and a host application
such as a search engine invokes a DDF processor and selects a description in response
to a user request for further processing. The description may be generated as prviously
described. In the next step 1202, the DDF processor parses the description into a
DesOM. After step 1202 the method continues at step 1204, where an associated set
of rules are accessed using the RuleSet attribute of the description scheme. These
set of rules may be serialised in the form of an XML document. In the next step 1206,
the first rule of the set is selected for processing.
[0249] The method then continues to decision block 1206, where a check is made whether a
pattern associated with the selected rule can be found in the DesOM. The manner in
which the pattern associated with the selected rule matches a pattern in the DesOM
is described in more detail in
7. Rule-based processing using the DesOM. If the decision block 1208 returns true(yes), then the processing continues at the
next step 810, where the inference or equivalence action associated with the rule
is initiated on the DesOM. These actions preferably initiate addition and removal
of attributes and elements from the DesOM thus modifying the DesOM. Afterwards, the
method selects the next rule in step 1211 and the processing returns to decision block
1208. If the decision block 1208 returns false(no), the processing continues at decision
block 1212, where a check is made whether all the selected rules have finally been
processed without action. In this way, the rules are iteratively processed until no
further changes can be made to the DesOM. This is advantageous in the situation where
some rules are dependent on other rules. If, on the other hand, the decision block
1212 returns true(yes), the processing continues at step 1216 where the extended DesOM
is output. The method then terminates at step 1218.
9. Method of Presenting Descriptions of Resources
[0250] A description could be used by many applications. Each application might exploit
different properties of the description and its defining description scheme. Some
of these applications will invariably need to represent description schemes and/or
descriptors in a graphical or pictorial manner. For example, many descriptors could
be graphically represented by icons and a user's interaction with either a description
or description scheme could be mediated by icon selection.
[0251] Presentation properties for descriptors could be included as part of the description
scheme however this can be non-ideal for two reasons. First, the role of the description
scheme and description is to describe classes of resources and a particular resource,
respectively, and it is preferable to keep both entities as concise and precise as
possible. Presentation information would result in extra presentation information
(eg., icons) being part of a description scheme (and perhaps descriptions) and would
therefore increase the storage and transmission costs for each description scheme.
Second, different applications might prefer to present descriptions and description
schemes in different ways. In other words, the presentation properties of descriptions
and description schemes can be application dependent.
[0252] It is advantageous, however, to have a set of presentation rules grouped in a rule
set that can be serialised, transported with and used in conjunction with the description
scheme so that other applications can, if they choose to, use a similar set of presentation
rules. This would not be the case if the presentation rules were tightly linked with
a particular application (ie., part of the application code base).
[0253] As with inference and equivalence rule sets, presentation rule sets can optionally
be linked with a description scheme by specifying the XML document containing the
presentation rule set as the value or part of the value of the ruleSets attribute
in the Description clement for the description scheme (see Section
3.1.2.2 Description Definition). Presentation rule sets can be included in the ruleSets attribute along with other
rule sets that might be concerned with inference and equivalence rules. In the Digital
Video Browser System, which is described in Section 13, the presentation rule sets
are stored with the description scheme in the ruleSets attribute. Alternatively, they
could be stored with the application rather than the description scheme. Presentation
rule sets stored as part of the description scheme are processed like inference or
equivalence rule sets. In other words, all the rules from the individual rule sets
are combined into a single rule set. Resolution of rules is performed on the basis
of rule order (as was described for inference rules in Section
8. Method of Extending Descriptions of Resources). If an alternative method of processing presentation rule set(s) is required then
the presentation rule set(s) are best stored with the application so the application
can control the processing.
[0254] Presentation properties can be attributed to the descriptor definitions in a description
scheme or the descriptor elements of a description using application-specific presentation
rules. Unlike, inference or equivalence rules, a presentation rule is typically applied
to an element definition in a DTD. Its role is to provide presentation behaviour for
the instances of the descriptors defined in the description scheme. In the Digital
Video Browser System (see Section 13), presentation rules are only applied to descriptor
definitions and not to descriptors within individual descriptions. However, it is
conceivable that some applications might benefit from an ability to define presentation
rules based on individual descriptors in descriptions. The rules in a presentation
rule set can be formulated in a similar way to inference or equivalence rule sets.
[0255] Preferably, the Action elements of presentation rules typically involve the addition
and removal of attribute definitions in element definitions (in the description scheme).
Consequently the rules are targeted at element definitions rather than elements. Alternative
embodiments could apply presentation rules to individual descriptions and therefore
the target of these rules would be elements rather than element definitions.
[0256] Presentation rules are used in the Digital Video Browser System described in Section
13 for the following functions:
- To classify descriptors as being structural (hence belonging in a Table of Contents)
or of an index nature (hence belonging to an Index);
- To assign icons to descriptors where the icons are assigned on a description scheme
basis (ie., by the addition of attribute definitions having default values to descriptor
definitions), and;
- To add "Selected" attributes to all selectable descriptor definitions so that selection
rules can interact with the presentation of the descriptions (eg, so the application
can differentiate visually between selected and non-selected descriptors).
[0257] The method involves associating a set of rules with a description scheme that can
influence the presentation properties of descriptors in descriptions which are conformant
with a particular description scheme. It is an advantage to have these presentation
rules grouped in a rule set that is either linked to a description scheme so that
applications can utilise the defined set of presentation properties if required. Alternatively
an application can select to use its own set of presentation rules.
[0258] Turning now to Fig. 13, there is shown a flow diagram of a method of
-visually presenting a description of a resource. In step 1300, the method commences
and a host application such as a search engine invokes a DDF processor. In the next
step 1301, a description is selected for presentation. This selection can occur by
way of user input or by way of another application. The method then continuesi at
step 1302, where the associated defining description scheme is read into memory. The
description scheme in memory comprises an array of element definitions where each
element definition has an array of attribute definitions. Alternatively, the DDF processor
can parse the description into a DesOM. After step 1302 the method continues at step
1304, where the presentation set of rules are accessed using the RuleSet Attribute
of the description. In the next step 1306, the first presentation rule of the set
is selected for processing.
[0259] The method then continues to decision block 1308, where a check is made whether a
pattern associated with the selected rule can be found in the DesOM. A pattern matching
process similar to that described in
7. Rule-based processing using the DesOM would be suitable. If the decision block 1308 returns true(yes), then the processing
continues at the next step 1310, where the attribute definition(s) associated with
the rule is removed or added to the array in memory. Afterwards, the method selects
the next rule in step 1311 and the processing returns to decision block 1308. If the
decision block 1308 returns false(no), the processing continues at decision block
1312, where a check is made whether all the selected rules have finally been processed
without action. In this way, the rules are iteratively processed until no further
changes can be made to the array in memory. This is advantageous in the situation
where some rules are dependent on other rules. If, on the other hand, the decision
block 1312 returns true(yes), the processing continues at step 1316 wherein a modified
description is created using said modified description scheme as a template. This
modified description is then output to an output device. For example, the modified
description and it's associated resources, such as digital video resources or DVDs,
can be rendered on a display or a printing device.
10. Method of Selecting Resource Descriptions
[0260] Selection rules can be used to formulate queries directed at collections of descriptions
(eg., digital libraries). A query can be viewed as a request to select those descriptions
or components of descriptions (ie., descriptors) that match a specified pattern. Like
inference and equivalence rules, selection rules are typically directed at elements
rather than element definitions. Unlike inference, equivalence and presentation rules,
however, selection rules may be generated on a one-off basis and not collected in
rule sets that are serialised in an XML document. For example, a query is usually
formulated with help from the user, then processed, and the results presented to the
user for their evaluation.
[0261] Selection rules often depend on presentation rules in that the selection action must
be able to be interpreted by the application and presented to user. For example, a
selection action could simply set a (presentation) attribute for descriptors that
match the specified pattern.
[0262] Selection rules are typically associated with the application. In the Digital Video
Browser System (see section 13), selection rules use the same grammar as all other
rules (see Section
7. Rule-based Processing using the DesOM). However, typically the only Action that is invoked by a selection rule is the Select
action. Consequently it would be possible to define a more specific grammar for selection
rules (eg., SelectionRules.dtd having just a Select action being allowed).
[0263] The Select action of a selection rule has three attributes which specify how the
selection action is implemented. The value of the attribute attName refers to the
attribute name used for a descriptor that is able to represent the action of being
selected. This attribute would typically have been generated using a presentation
rule. If the element matched by the pattern does not contain such an attribute, then
the selection process will search for ancestors of the matched element in the DesOM
(ie., up the description tree) until it locates an element with the specified attribute
name. In the above DTD this attribute name is provided with a default value of "selected".
The value of the second attribute attValue refers to the value that the "selected"
attribute should be assigned in order to indicate selection. The DTD also provides
a default value of "YES". The third attribute specifies whether all selectable ancestors
should also be selected. So, for example, if a user selects a Shot descriptor because
of a matched descriptor contained in the Shot descriptor, then the user should also
select the ancestors of the Shot descriptor (ie, the Scene descriptor and the VideoClipDescription
descriptor).
[0264] In this way, the Select element provides information to the application on which
elements have matched the specified pattern in the selection rule. Clearly the application
needs to be aware of the attribute used to provide this information, hence the interaction
between presentation and selection rules. In the Digital Video Browser System (see
Section 13), selection rules are used to implement searches in a Digital Video Library.
[0265] The method involves that of representing queries by selection rules which attempt
to find matches to a rule's specified element pattern. The "select" action that is
executed on a successful pattern match typically modifies attributes established by
presentation rules, so that the selection process can interact with the application.
[0266] Turning now to Fig. 14, there is shown a flow diagram of a method of selecting one
or more descriptions or part of one or more descriptions of a resource. In step 1400,
the method commences and a host application such as a search engine invokes a DDF
processor. In the next step 1402, a user inputs a query which is formulated as a rule
in step 1404.The search engine then selects in step 1405 a first description for evaluation.
The method then continues at step 1406, where the DDF processor parses the description
into a DesOM.
[0267] The method then continues to decision block 1408, where a check is made whether a
pattern associated with the selected rule can be found in the DesOM. The manner in
which the pattern associated with the selected rule matches a pattern in the DesOM
is described in more detail in
7. Rule-based processing using the DesOM. If the decision block 1408 returns true(yes), then the processing continues at the
next step 1410, where the select action associated with the rule is initiated on the
DesOM. The details of the select action is described above. Afterwards, the method
then continues at decision block 1412 where a check is made whether the last description
has been searched. If the decision block returns false(no) the processing continues
at step 1414 where the next description is selected. Otherwise, the processing continues
at step 1416, where the results of the searching process is output. The method then
terminates at step 1418.
11. Method of Translating Descriptions of Resources
[0268] Often descriptions of resources will be in a language different from the request.
Rather than store copies of the descriptions in each language, the method stores only
one copy of the descriptions in one language. Preferably, the language is English.
The method is then provided with a number of rule sets that enable the translation
of the descriptions to the language of the request. For example, the description may
have a "colour" attribute and a colour attribute value "red". If the request is received
in French, then the method will translate to description to French. In the example
given, "colour" and "red" will be translated to their French equivalent. This is a
form of inter-language equivalence. This procedure is similar to the way Inference
Rules are processed, but on a conditional basis. Inference rules are preferably not
processed on a conditional basis as described here for translation rules.
[0269] Turning now to Fig. 15, there is shown a flow diagram of a method of translating
a description of a resource. In step 1500, the method commences and a host application
such as a search engine invokes a DDF processor and selects a description in response
to a user request for further processing. In the next step 1502, the DDF processor
parses the description into a DesOM. After step 1502 the method continues at decision
block 1503, where a check is made whether the language of the request is different
from the language of the description. This check is accomplished by comparing the
language attributes of both the request and the description.
[0270] If the decision block 1503 returns true(yes), the processing continues at step 1504,
where an associated translation set of rules are accessed using the RuleSet Attribute
of the description. These translation set of rules may be serialised in the form of
an XML document. On the other hand, if the decision block returns false(no) then the
processing continues at step 1516. After completion of step 1504, the method continues
at step 1506, where the first rule of the set is selected for processing.
[0271] The method then continues to decision block 1506, where a check is made whether a
pattern associated with the selected rule can be found in the DesOM. The manner in
which the pattern associated with the selected rule matches a pattern in the DesOM
is described in more detail in
7. Rule-based processing using the DesOM. If the decision block 1508 returns true(yes), then the processing continues at the
next step 1510, where the translation action associated with the rule is initiated
on the DesOM. These actions initiate the removal and addition of attributes and elements
from the DesOM. The removal and addition action substitutes the language of the attributes
and elements for another. Afterwards, the method selects the next rule in step 1507
and the processing returns to decision block 1508. If the decision block 1508 returns
false(no), the processing continues at decision block 1512, where a check is made
whether all the selected rules have finally been processed without action. If, on
the other hand, the decision block 1512 returns true(yes), the processing continues
at step 1516 where the extended DesOM is output. The method then terminates at step
1518. Alternatively it is also possible to include an action of a rule which invokes
a DescriptorHandler method to translate the content of the selected Descriptor.
12. First Embodiment of Apparatus
[0272] The processes described in relation to Figs. 1A to 15 can be practiced using a conventional
general-purpose computer, such as the one shown in Fig. 19 wherein the processes may
be implemented as software executing on the computer. In particular, the method steps
are effected by instructions in the software that are carried out by the computer.
The software may be divided into two separate parts; one part for carrying out the
processing steps; and another part to manage the user interface between the latter
and the user. The software may be stored in a computer readable medium, including
the storage devices described below, for example. The software is loaded into the
computer from the computer readable medium, and then executed by the computer. A computer
readable medium having such software or computer program recorded on it is a computer
program product. The use of the computer program product in the computer preferably
effects an advantageous apparatus in accordance with the embodiments of the invention.
[0273] The computer system 1900 consists of the computer 1902, a video display 1916, and
input devices 1918, 1920. In addition, the computer system 1900 can have any of a
number of other output devices including line printers, laser printers, plotters,
and other reproduction devices connected to the computer 1902. The computer system
1900 can be connected to one or more other computers via a communication interface
1908b using an appropriate communication channel 1930 such as a modem communications
path, a computer network, or the like. The computer network may include a local area
network (LAN), a wide area network (WAN), an Intranet, and/or the Internet
[0274] The computer 1902 itself consists of a central processing unit(s) (simply referred
to as a processor hereinafter) 1904, a memory 1906 which may include random access
memory (RAM) and read-only memory (ROM), input/output (IO) interfaces 1908a, 1908b
& 1908c, a video interface 1910, and one or more storage devices generally represented
by a block 1912 in Fig. 19. The storage device(s) 1912 can consist of one or more
of the following: a floppy disc, a hard disc drive, a magneto-optical disc drive,
CD-ROM, magnetic tape or any other of a number of non-volatile storage devices well
known to those skilled in the art. Each of the components 1904 to 1912 is typically
connected to one or more of the other devices via a bus 1914 that in turn can consist
of data, address, and control buses.
[0275] The video interface 1910 is connected to the video display 1916 and provides video
signals from the computer 1902 for display on the video display 1916. User input to
operate the computer 1902 can be provided by one or more input devices 1908b. For
example, an operator can use the keyboard 1918 and/or a pointing device such as the
mouse 1920 to provide input to the computer 1902.
[0276] The system 1900 is simply provided for illustrative purposes and other configurations
can be employed without departing from the scope and spirit of the invention. Exemplary
computers on which the embodiment can be practiced include IBM-PC/ATs or compatibles,
one of the Macintoshâ„¢ family of PCs, Sun Sparcstation â„¢, or the like. The foregoing
are merely exemplary of the types of computers with which the embodiments of the invention
may be practiced. Typically, the processes of the embodiments, described hereinafter,
are resident as software or a program recorded on a hard disk drive (generally depicted
as block 1912 in Fig. 19) as the computer readable medium, and read and controlled
using the processor 1904. Intermediate storage of the program and pixel data and any
data fetched from the network may be accomplished using the semiconductor memory 1906,
possibly in concert with the hard disk drive 1912.
[0277] In some instances, the program may be supplied to the user encoded on a CD-ROM or
a floppy disk (both generally depicted by block 1912), or alternatively could be read
by the user from the network via a modem device connected to the computer, for example.
Still further, the software can also be loaded into the computer system 1900 from
other computer readable medium including magnetic tape, a ROM or integrated circuit,
a magneto-optical disk, a radio or infra-red transmission channel between the computer
and another device, a computer readable card such as a PCMCIA card, and the Internet
and Intranets including email transmissions and information recorded on websites and
the like. The foregoing are merely exemplary of relevant computer readable mediums.
Other computer readable mediums may be practiced without departing from the scope
and spirit of the invention.
[0278] The methods of the invention may alternatively be implemented in dedicated hardware
such as one or more integrated circuits performing the functions or sub functions
of methods of the invention. Such dedicated hardware may include graphic processors,
digital signal processors, or one or more microprocessors and associated memories.
13. Second Embodiment of Apparatus - Digital Video Browser System
[0279] A Digital Video Browser System in accordance with a second embodiment of the apparatus
is described in this section. The functionality of the Digital Video Browser System
is enabled by the descriptions of digital video that are automatically generated using
a description scheme, designed for digital video resources, such as that included
in Appendix D.
[0280] The Digital Video Browser System allows a user to browse the digital video in a non-linear
manner, manually annotate the digital video to provide additional descriptive information
that was not able to be automatically generated, and to search for the presence of
various descriptors in a description. It should be clear to the reader that all this
functionality is enabled by an interaction of the user with the description scheme
and the individual descriptions of the digital video resources and that the browser
that is described in the following section can in essence be applied to any other
electronically-accessible resource.
[0281] An example of such a Digital Video Browser System is shown in Fig. 16. The system
contains a Video Browser Panel 1600 which consists of a Viewing Panel 1601, a Table-of-Contents
(or TOC) Panel 1602, and an Index Panel 1603. Outside of the Video Browser Panel 1600
but within the system are three buttons required for user interaction; a Search button
1605, a Play button 1606, and an On/Off button 1607.
[0282] User interaction with the panels of the Digital Video Browser System can be mediated
by a touch-sensitive Video Browser Panel, however this feature is not necessary for
the operation of the system. The operation of the Digital Video Browser System will
now be discussed in the terms of Fig. 16.
[0283] When a new digital video resource is added to the Digit Video Browser System a predetermined
description scheme is applied to the digital video resource resulting in the content
creation methods of the relevant descriptor handlers in the description schemes being
initiated. Other implementations might provide more than one description scheme which
can be applied to the digital video resources. For example, a Digital Video Browser
System might provide the description schemes contained in Appendices B and D. In such
an embodiment the user would require a means to select the description scheme that
he/she would like to apply to each new digital video resource. So, for example, if
he/she was adding a new digital video resource containing the footage from a football
match then he/she would most likely use the description scheme in Appendix B, however
if the digital video resource contained same footage of a recent holiday, then it's
likely that the description scheme contained in Appendix D would be more appropriate.
[0284] If more than one description scheme is available then the selection of the most appropriate
description scheme to use could also be automated to some extent. The resource to
be described could be analysed to see if it contained key features that typically
indicate the use of a particular description scheme. For example, the sound track
of a digital video resource could be analysed for repetitive whistle sounds arising
from a referee's whistle. If detected, such sounds could provide evidence for the
use of a particular description scheme (eg., the description scheme shown in Appendix
B).
[0285] In a simple description scheme such as that included in Appendix B there is a single
descriptor handler specified for the description (which is also a descriptor), which
generates the entire content for the description.
[0286] In other description schemes, more than one descriptor may have an associated descriptor
handler which is responsible for automatically generating the content of just that
descriptor. For example, consider the description scheme shown in Appendix D. The
VideoDescription descriptor D1 has an associated descriptor handler D2 which provides
a method to automatically segment the digital video resource into a series of individual
shots. The Shot descriptor D3 has an associated descriptor handler D4 which provides
a method to automatically select a key frame from a specific shot and then generate
a series of semantic labels which provide some information about the content of the
particular shot (eg., whether or not the shot contained people, was an indoors or
outdoors shot, etc.). These descriptor handler methods are executed on the creation
of a descriptor in the description being generated. Therefore the description can
be progressively constructed using the description scheme (effectively as a template)
and the set of descriptor handlers that provide the methods for automatically generating
the content for their relevant descriptors. An example of such a generated description
is provided in Appendix E.
[0287] In the case of the Digital Video Browser System depicted in Fig. 16, the descriptors
able to be accessed in the Index Panel, rather than the TOC Panel are classified as
Index Descriptors. The classification of descriptors as Index or TOC descriptors is
achieved using presentation rules (see Section
8. Method of Presenting Descriptions of Resources), with each description scheme being used by the Digital Video Browser System having
a corresponding presentation rule set. For example, a presentation rule could be applied
to each of the descriptor definitions in the description scheme to add an attribute
definition to the descriptor's definition for the purposes of this classification.
The added attribute definition could have a attribute default of #FIXED "Index" or
#FIXED "TOC" to classify an Index and TOC descriptor, respectively. [Note: The use
of the #FIXED keyword in the default value means that changing the value of the classifier
from its default value results in an invalid XML construct and hence an invalid description.]
[0288] Selecting which descriptors are to be used as Index descriptors is similar to selecting
which key words or phrases you would include in the index of a book. In other words,
it is an authoring task that results in presentation rules. In general, a descriptor
that is classified as a TOC descriptor represents a structural element of the resource
(ie., a component that would normally appear in the TOC of a book). So, for example,
a Shot descriptor is a TOC descriptor. An Index descriptor typically represents a
property of a TOC descriptor (eg., a Shot descriptor could contain people scenes,
be an indoor or outdoor scene, etc.).
[0289] The Index descriptors are the leaf nodes of the internal tree structure used to represent
the description [The internal representation of descriptions is discussed in detail
in Section
2.3 Description Object Model (DesOM)]. In the absence of presentation rules, this property can also be used to implicitly
differentiate between Index and TOC descriptors in an implemented Digital Video Browser
System. In the Digital Video Browser System, explicit differentiation between Index
and TOC Descriptors is achieved using presentation rules. A set of presentation rules
applicable to the description scheme in Appendix D is shown in Appendix F.
[0290] The Digital Video Browser System has access to a collection of digital video resources,
which is hereinafter referred to a Digital Video Library. A newly described digital
video resource can be simply appended to an existing collection of described digital
video resources. Alternatively (see Section
11. Remote Digital Video Browser Devices), the user can insert a new item at the desired location using a drag-and drop means.
The Digital Video Library is itself a resource able to be described. Therefore, on
initialising the Digital Video Browser System a description scheme for a Digital Video
Library is used to automatically generate a description for the Digital Video Library.
[0291] The description of the Digital Video Library can be very simple containing just a
hierarchical representation of the individual descriptions of digital video resources
described in the library. In other words, the description need not know about the
location of the digital video resources described in the library. It is merely a catalogue
of the descriptions of the digital video resources stored in the library. Each individual
description has a reference to its corresponding digital video resource.
[0292] An example of a description scheme for a Digital Video Library is included in Appendix
G. The Digital Video Library's description can contain zero or more Section elements
or zero or more Item elements, where each Item element refers to an individual description
in the Digital Video Library (ie., an XML document). A description of a Digital Video
Library conforming to the description scheme included in Appendix G is shown in Appendix
H.
[0293] During browsing the user can select sections of Digital Video Library by selecting
the relevant descriptors in the TOC Panel 1602 in the Video Browser Panel 1600. This
selection method provides non-linear access to the digital video resource(s). Typically
these selections are highlighted in the TOC panel to indicate which are currently
selected. The user can choose to play all the highlighted selections by pressing the
"Play" button 1606.
[0294] Alternatively the user can search for sections, items or parts of items of the Digital
Video Library by selecting relevant Index descriptors in the Index Panel 1603. In
a simple Digital Video Browser System implementation, the Index descriptors might
imply simple boolean presence of a specified feature. For example, the PeopleScene
Index descriptor (see D5 in Appendix D) could indicate whether people are either present
or absent from the shot. In a more sophisticated Digital Video Browser System the
Index descriptors might require some representative value. For example, a "Date" Index
descriptor would require a specified value before a search could be performed.
[0295] Searches can be performed within a TOC context in the Digital Video Library. For
example, if a user wanted to search for PeopleScene descriptors within a specific
digital video resource, the user could select the TOC descriptor for that particular
resource in the TOC Panel 1602 and then select the desired Index descriptor in the
Index panel 1603 and press the "Search" button 1605 in the Digital Video Browser System.
The search process would then result in all TOC descriptors that satisfied the search
criteria becoming selected (eg, highlighted) in the TOC Panel 1602. The user could
then select to play all the selected sections of the digital video resource by pressing
the "Play" button 1606.
[0296] Searches can be implemented in the Digital Video Browser System using selection rules
(see Section
10. Method of Selecting Resource Descriptions). The TOC context is automatically inserted as part of the pattern of the selection
rule. The search process applies the selection rule pattern to each relevant description
and updates a selection attribute that has been added for all selectable attributes
using a presentation rule. Selectable attributes will vary between description scheme
and application. In the case of the description scheme included in Appendix D the
only descriptors that might be classified as selectable would be the VideoDescription
and Shot descriptors (see the presentation rules in Appendix F).
[0297] The Digital Video Browser System also provides functionality for manual annotation,
in conformance with the description scheme, of a digital video resource. If a particular
TOC descriptor is selected, then the relevant Index descriptors 1609 can be displayed
in the Index Panel 1603. The Index descriptors are preferably represented by icons
(which in preferably are specified by presentation rules targeted at the descriptor
definitions). The selected TOC descriptor can be viewed (played) and then manually
annotated by dragging icons representing the Index descriptors (eg., 1610) into an
Annotation Region 1604 of the Viewing Panel 1601. Annotations created in this fashion
are then added to the description of the resource and are available for subsequent
browsing.
[0298] Annotations in the form of titling various TOC Descriptors could also be possible
in some implementations of a Digital Video Browser System. For example, in a Digital
Video Browser System implemented in software on a regular personal computer, the screen
representation of the Descriptor could be selected and then the title for the descriptor
could be entered using the computer's keyboard. In alternative embodiments, in which
access to the Video Browser Panel 1600 is provided via a touch-sensitive display,
user entry of textual titles could be mediated by a pen interface or via a method
whereby a particular descriptor is selected by touch, and the title communicated by
the user speaking the title words and a speech-to-text module in the Video Browser
System converting the spoken words to text and displaying the result where a title
is expected on the display.
[0299] Whenever new descriptions are retrieved for browsing the description is processed
into a DesOM. Before the description is actually presented in the Video Browser System,
any inference or equivalence rules (see Section
8. Method of Extending Descriptions of Resources) that are associated with the description's description scheme are processed. This
processing involves iterating through the defined inference rules until no more changes
can be made to the description. Clearly, this rule processing requires that there
are no circular dependencies in the rule set The inference and/or equivalence rules
will result in the creation of new descriptors which have been inferred from those
that were part of the serialised description. Preferably, any new descriptor's created
by this process will have been defined as part of the relevant description scheme
(and as such will have been classified as an Index or TOC descriptor). The inference
rules will need to be reprocessed in the event of any annotations being created.
14. Third and Fourth Embodiment of Apparatus - Remote Digital Video Browser Devices
[0300] The Digital Video Browser System described in the previous section can also be implemented
as a dedicated remote device. In this section, two possible remote device embodiments
of the Digital Video Browser System are described with respect to Fig. 17 and Fig.
18.
[0301] The first remote device of the Digital Video Browser System is shown in Fig. 17.
In this embodiment the Video Browser 1700, contains no storage for the Digital Video
Library. The Video Browser 1700 communicates with a Server 1710 using a wireless transmitter/receiver
1702 and a wireless connection 1703. The Server 1710 has a connection 1717 with a
storage device that contains the Digital Video Library 1711. All the digital video
resources that can be browsed by the Video Browser are stored in this Digital Video
Library. Preferably, in this remote device all the descriptions of the digital video
resources are also stored in this library 1711. The Server 1710 also has a connection
1714 to a large display 1712 that can be used for public viewing of the digital video
resources. Preferably, the connections between the Server 1710 and the Digital Video
Library 1711 and between the Server 1710 and the large display 1712 are wired connections.
[0302] New digital video resources can be added to the Digital Video Library 1711 which
is directly connected to the Server 1710 independently of the Video Browser device
1700. As the resources are added to the Digital Video Library 1711 (from, for example,
a digital video camera), descriptions for the digital video resources are automatically
generated using the description scheme. Also at this time, usually after the description
has been generated, the user could optionally title sections of the digital video
resource. These titles would then be visible when browsing using the Digital Video
Browser device.
[0303] On power-up the Video Browser device connects to the Server 1710 using the wireless
connection 1703. The Server 1710 communicates to the Digital Video Browser device
a description of the Digital Video Library. This description, like descriptions of
the digital video resources, conforms to a description scheme (in this case for a
Digital Video Library), and is serialised in an XML document. An example of a description
of a Digital Video Library is shown in Appendix H.
[0304] The remote Digital Video Browser device 1700 can either store the relevant description
schemes permanently, or download these description schemes at the time of making its
connection with the Server 1710. The latter method of obtaining the description schemes
is preferred. The description of the Digital Video Library and the relevant description
schemes contain all the information required to display an Index and TOC panel on
the Digital Video Browser device 1700. The user can then use the Digital Video Browser
device to navigate through the Digital Video Library, selecting or searching for video
resources to view. Preferably, the navigation through the TOC and Index panels is
enabled via a touch-sensitive screen. Other methods of navigation (eg., a pen or simple
keyboard) could also be used.
[0305] Only when a Digital Video Browser user selects to "Play" a particular selection of
digital video resources, is it necessary to transmit the required digital video resources
from the Digital Video Library 1711 to the remote Digital Video Browser device 1700.
Preferably the digital video resources are stored and transmitted in compressed form
(eg., MPEG-1 or MPEG-2 ) therefore minimising the bandwidth of the required wireless
connection 1703 between the Server 1710 and the remote Digital Video Browser device
1700.
[0306] The remote Digital Video Browser device can optionally have an additional button
(to those shown in Fig. 16), which can be used to direct the Viewing Panel 1701 of
the remote Digital Video Browser device to a large display 1712 connected to the Server
1710. This redirection can be achieved by transmitting a description of the required
presentation (ie., an XML document) from the remote Digital Video Browser device 1700
to the Server 1710. This description would conform to a Video Presentation Description
Scheme (eg Appendix I) that could be as simple as just a list of all the selected
sections of the selected digital video resources. An example description of a video
presentation is shown in Appendix J.
[0307] The video browser system generates a description of a video presentation by first
reading the description scheme for the presentation (eg Appendix I). This description
scheme contains definitions of descriptors required for the video presentation (eg
VideoDescription Reference, Shot Reference descriptor definitions in Appendix I).
The video browser system then generates the description of the presentation using
the description scheme read by the browser and information about the resources that
have been selected for presentation. The result of this step is a description such
as shown by way of example in Appendix I. This description can then be directed to
an output device 1712 for rendering.
[0308] Preferably, this description is interpreted by the Server 1710 and the corresponding
sections of the selected digital video resources would be rendered to the large display
1712. The rendering is performed by the Server 1710 and pixel data would be transmitted
over the connection 1714, however if the large display 1712 had the processing ability
to decode the compressed digital video resource, then the compressed resource could
be transmitted over the connection 1714 and then decoded and rendered in the large
display 1712.
[0309] Clearly, presentation rules could be applied to the presentation of the selected
items in the same way as presentation rules are applied to a description of a digital
video resource. Some presentation rules that could be applicable to the presentation
of digital video resources include rules that specify the type of transitions to be
inserted between shots of a particular digital video clip (eg., fades, cuts, wipes,
etc.) and whether clip titles are to be rendered over the presented video and the
style of title rendering to be used. These rules could be collected in a presentation
rule set that is linked with the Video Presentation Description Scheme in the same
way that sets of presentation rules could be linked to the Digital Video Resource
Description Scheme (see Appendix D).
[0310] Alternative Digital Video Browser implementations could allow users to specify additional
presentation rules for the presentation of selected digital video resources. For example,
an implementation could allow a user to specify whether a particular selection was
to be played at recorded, slow or fast speed. Altering the speed of video playing
can provide interesting presentation effects. Similarly, the Digital Video Browser
user might also be able to specify the types of transitions to use on a one-off presentation
basis rather than a default basis as provided by rules linked to the Video Presentation
Description Scheme. These one-off presentation rules can be combined into a single
rule set which is referenced by the Description element of the presentation description
that is communicated to the Server 1710 when the user chooses to play the selected
digital video resources (whether on the Digital Video Browser device itself or, more
likely, when the presentation has been re-directed to the large display 1712).
[0311] An example of a Video Presentation Description Scheme, which could be used with the
Video Description Scheme shown in Appendix D, is shown in Appendix I. In this description
scheme, a standard set of presentation rules is provided as part of the description
scheme. These rules have been collected into a rule set and stored in the XML document
which, in the case of the example is called "VideoPresentationRules.xml". The rule
set has then been referenced by the description scheme by specifying an ENTITY for
the ruleSets attribute I1 of the VideoPresentationDescription element. The attribute
userPresentationRules I2 has been added to the VideoPresentationDescription subclass
of the Description element to be able to contain an ENTITY that specifies an xml document
that contains any presentation-specific rules.
[0312] An example of a video presentation description that conforms to the Video Presentation
Description Scheme, which is included in Appendix I, is shown in Appendix J. A set
of presentation-specific rules has been specified for the particular presentation
using the userPresentationRules attribute of the VideoPresentationDescription element
(see J1). Clearly the example description scheme and presentation description included
in Appendices I and J pertain to the Video Description Scheme included in Appendix
D since they refer to particular descriptors in that description scheme. For example,
the VideoDescriptionReference element contains zero or more references to Shot elements
in the referenced video descriptions. In particular the shotIDRef element J2 specifies
a particular shot descriptor in the description contained VideoEgl.xml, by using a
reference to the ID of that descriptor in the description. It is not necessary to
use a Video Presentation Description Scheme that is directed so specifically at a
particular description scheme. For example, if a Digital Video Browser System was
implemented with more than one description scheme, then a more general Video Presentation
Description Scheme can be used.
[0313] The ability to be able to re-direct the Viewing Panel 1701 to a large display 1712
connected to the Server 1710 is a useful feature as the user can select the sections
of his/her Digital Video Library that he/she wishes to share with an audience using
the remote Digital Video Browser device. That selection can then simply be played
to the large display 1712.
[0314] A second remote device implementation of the Digital Video Browser System is shown
in Fig. 18. In this implementation the Digital Video Browser 1800 is implemented as
a remote device that has a capability to read Digital Video Disks (DVDs). Typically
each DVD is treated like an independent Digital Video Library and consequently each
DVD has its own description of the Digital Video Library contained on the DVD. When
the DVD 1815 is inserted into the remote Digital Video Browser device 1800 the Video
Browser 1800 reads the description of the Digital Video Library contained on the DVD.
In this device the description scheme required to interpret the Digital Video Library
would preferably reside in the remote Digital Video Browser device, however it is
conceivable that the description scheme could also be located on each DVD. Similarly
the description schemes required to interpret the descriptions of the digital video
resources could either be located on the DVD or in the remote Digital Video Browser
device. In the preferred implementation of this device, all the required description
schemes are located in the remote Digital Video Browser device 1800. New description
schemes for digital video resources can be downloaded via the wireless transmitter/receiver
1802 and wireless connection 1804 to a server or computer 1813 connected to a network
1814. Alternatively, the remote Digital Video Browser can be docked at a server or
networked computer for the download of new description schemes.
[0315] Once the description of a Digital Video Library has been read from the DVD 1815 then
the user can navigate through this Digital Video Library as described previously.
Sections of described digital video resources can be selected and played on the remote
device. The device is in many respects very similar to the device depicted in Fig.
17, with the exception that it does not require a Server to store the digital video
resources and descriptions.
[0316] Sections of the selected digital video resources can be selected for viewing on a
large display 1810 that has a wireless connection 1803 with the remote Digital Video
Browser device. This large display 1810 must either contain, or be directly connected
to, a processor able to decode and render the compressed digital video resource that
is transmitted via the wireless connection 1803. As with the remote device depicted
in Fig. 17, a description of the required presentation is communicated to the large
display 1810. In addition, any digital video resources required for the presentation
description to be rendered must also be communicated. These resources are typically
communicated in compressed (encoded) form (eg., MPEG-1 or MPEG-2). The processor either
contained in, or directly connected to, the large display 1810 renders the presentation
using the presentation description and its associated digital video resources. The
rendering process can typically adapt to the resolution of the large display 1810,
which is usually greater than that of the handheld device.
[0317] In the preferred implementation of this device 1804, if the description of the required
presentation requires that only particular sections of a selected digital video resources
be presented, then these required sections can be isolated from the original digital
video resource, recorded if necessary in the handheld device, and then communicated
to the large display 1810. This approach reduces the communication bandwidth of the
wireless connection 1803. Alternatively, the entire digital video resource can be
communicated and the processor that renders the presentation will need to extract
the relevant sections of the digital video resource(s). The latter implementation
is more costly in bandwidth but does not involve recording of digital video resources
in the remote device.
[0318] In order to facilitate resource discovery on different DVDs, this remote Digital
Video Browser device can also have an ability to generate printed DVD covers that
display the contents of the DVD in a graphically pleasing manner. This printed presentation
can be achieved in substantially the same manner as described for a vide presentation.
This facility can be achieved using a wireless connection 1805 to either a printer
with some processing ability 1812, or to a computer directly connected to a printer
(not shown in Fig. 18). Typically the Digital Video Browser device would send to the
printing device (1812 or the computer directly connected to a printer), a description
of the (printed) presentation that is to be the printed DVD cover.
[0319] Description schemes for this presentation could be designed just as they can be designed
for video presentations (eg., see Appendix I.). For example, at the simplest level
the Digital Video Library description could form the basis of the printed presentation.
Presentation rules could then be used to specify the spatial layout and colour arrangement
of the printed presentation, and also the association of icons or key frames to particular
descriptors in the description. The presence of visual reminders of the content of
the DVD, such as icons or key frames, are important for purposes of identification
and retrieval.
[0320] A processor, which is located either in the printer 1812 or in a computer connected
to the printer could then use the description of the required printed presentation
and any provided presentation rule sets to render a DVD cover for the particular DVD
using the provided key frames. This processor would need to be able to interpret the
description of the printed presentation.
15. Fifth Embodiment of Apparatus - Media Browser System
[0321] Browsing of electronically-accessible resources other than digital video can also
be enabled by descriptions that conform to identified description schemes. In an alternative
embodiment, a Media Browser System can enable the description-based browsing of any
electronically-accessible resource. Although the description schemes used to describe
these different resources might be significantly different, a common browsing framework,
called here a Media Browsing System, can be used. The Video Browser System described
in Section 13 is a more specific embodiment of the Media Browser System described
in this Section. However, many aspects of the Video Browser System can also be implemented
in the Media Browser System.
[0322] The browsing method requires that each resource is consistently described (eg., using
the DDF) according to a description scheme and the resulting description contains
a link to the resource or sections of the resource. Preferably, the DDF (see Section
2) is used to provide a consistent method of describing resources, however alternative
methods of describing resources could also be used. For example, other schema languages
such as XML-Schema of the W3C could also be used. In the case of XML-Schema, core
descriptor elements can be defined in substantially the same way as described for
the DDF in section 3.1.2.
[0323] In addition, in the embodiment described here, descriptor components of description
schemes are further classified using predetermined classifications that provide axes
of access to the resources. The preferred axes of access used in this embodiment are
the structural access (Table of Contents(TOC) access) and the index access. These
axes have been used because humans are familiar with their use in, for example, reference
books. Whereas the TOC-axis of access provides access to resources on the basis of
context (ie., where a resource or section of a resource exists in relation to other
resources or sections of resources), the index-axis effectively provides context-free
access to resources (just as an index in a reference book). It should be clear to
those skilled in the art of browsing technologies that the value of this classification
of description components into TOC and index axes of access is that a Media Browser
System can act both as a browser (in the sense of current web-browsing technology)
and a search engine in one.
[0324] It is possible to use different axes of access and the number of axes is not limited
to two. For example, the Media Browser System could use an interface similar to that
shown in Fig. 16 for the Digital Video Browser System, but having a further axis of
access on the left hand side of the viewing panel to provide access to the digital
video via audio events. Another variation is one where more than one TOC axis can
be used to allow more than one structural view to browsable content. For example,
one TOC might provide browsing access using content category (eg. birthday images)
and another axis might provide access by date of creation.
[0325] The predetermined classification of descriptor components into axes of access can
be achieved using the methods described for the Digital Video System (see Section
13).
[0326] Any electronically-accessible resource can be accessed by the Media Browser System
using a description of the resource as long as the Media Browser System can access
the description scheme to which the description conforms and a processor for the class
of resource. For example, a digital video resource might require a MPEG-1 or MPEG-2
processor (player) to be present, an image might require a JPEG viewer and an audio
object might require an MP3 audio processor. These processors are preferably stored
with the browser and new processors are able to be downloaded when required by a resource.
The Media Browser using the DDF, identifies the processor required by the resource
by the relevant NOTATION declaration in the description scheme (see Section 3.1.2.2).
[0327] The resources can be an electronic document or other resources available over the
web. The resource can also be an electronic device. The description that appears in
the TOC axis can also be located at different sites on the web. In this sense, the
TOC axis can be compared to a set of description bookmarks. A TOC item may contain
links to other descriptions, to individual resources or sections of resources (eg.
a spatio temporal extent in a digital video).
[0328] It should be clear to someone skilled in the art that if resource library providers
on the web described their resources using a consistent method such as the DDF, a
TOC axis could be made to extend over all resource libraries of interest to a particular
user. In other words, the TOC could represent an information landscape over which
a user could browse and search for resources, This has the advantage of the user not
having to visit each digital resource library site in turn in order to search for
desired resources.
[0329] The media can be browsed, annotated and searched in the same way as that described
for digital video resources (see Section 13). Clearly, the descriptors that appear
in the different axes during browsing will vary depending on the description schemes
that are relevant with regard to the browsing context at any particular instance.
For example, if more than one description is currently in context and these descriptions
conform to different description schemes then an index panel will reflect all the
descriptor components which have been classified as index descriptors in the relevant
description schemes. In other words, the set of index descriptors that at shown at
any time in the Media Browsing System represents the union of the sets of index descriptors
that arise from all the description schemes that are relevant to the descriptions
that are currently in context. In other embodiments, it would be possible to show
only those index descriptors that represent the intersection of the sets of index
descriptors that arise from the relevant description schemes. In this case, an index
descriptor would need to exist in each of the relevant description schemes before
it could be provided by the Media Browsing System as an index for browsing.
[0330] The selection of a TOC context for searching using the index panel is implemented
in the Media Browser System using the method that is described for the Digital Video
Browser System (see Section 13).
[0331] Links between descriptor components of descriptions and spatially and/or temporally
localised sections of the resources can be represented in the descriptions using locators
and extents (see Section 3.1.4 for how these constructs are used in the context of
the DDF). Preferably, the navigation of these links is performed automatically by
the Media Browser when the user selects to play/view the selected resource(s). The
Media Browser identifies the spatial and/or temporal extent(s) that are linked to
a selected descriptor and plays/views the section(s) of the resource which contain
the extent(s).
[0332] For example, a descriptor could refer to a spatially and temporally localised object
in a digital video. This object can be represented spatially by a rectangular bounding
box and temporally by a range of image frames. If a user selected the object's descriptor
and chose to play the selections, the Media Browser would automatically identify the
frames which contained the object and play that section of the video only.
[0333] The Media Browsing System differs from existing HTML browsers in that the entities
mediating the browsing [eg., the (DDF) descriptions] contain only descriptions of
the resources to be browsed. In the case of the HTML browser, the HTML documents represent
the resource, control the presentation of the resource and also contain some description
of the resource (the META tag). The browser typically does not use the descriptive
information. In contrast, the entities mediating the browsing in the Media Browser
System are ONLY descriptions of resources. These descriptions contain links to the
relevant resources or sections of the resource to be viewed or played. The key and
most obvious advantage obtained by browsing using descriptions of resources is browsing
access to non-textual resources (eg., digital signals). However, the Media Browser
style of browsing also uses the descriptive information available about resources
to provide a richer browser interface that can include annotation and searching. This
richer interface is also available to textual documents (eg., XML and HTML documents).
[0334] Fig. 20 shows an example of the Media Browsing System in accordance with the fifth
embodiment The Media Browser system 2000 contains a viewing pane 2006, a Table of
Contents (or TOC) panel 2002 and an Index panel 2004. The TOC panel 2002 displays
a Table of Contents of all resources and resource libraries that are of interest to
a user. The TOC effectively represents a personal library where individual items are
typically distributed across the web. It is like a set of bookmarks or pointers into
different description libraries or single descriptions.
[0335] The TOC axis provides an information landscape for the user to browse. Individual
items of TOC can be:
(i) expanded to show contained items or collapsed to hide contained items;
(ii) selected to play/view;
(iii) selected for the current context (eg. to search).
[0336] Preferably, these browsing functions are enabled in the following way. Each TOC item
consists of a node symbol (eg. a large bullet symbol) and a node content (which is
defined by the corresponding descriptor in the description). The node content can
be an image ( such as a key frame as is preferably used to represent a section of
video) or some text which can describe the personal item (whether it represents a
section in the personal library or information landscape, or a resource).
[0337] TOC items are expanded and collapsed by checking on the node symbol (ie. to node
symbol acts as a toggle). It is preferable for the node symbol to indicate whether
an item can be expanded. For example, the node symbol can be displayed as an open
bullet symbol if it has contained items (ie. can be expanded) and a filled bullet
symbol if it cannot be expanded).
[0338] TOC items can be selected for viewing/playing by clicking on the node content. Preferably,
a single click indicates that an item should be queued to be viewed/played. A double
click action results in immediate viewing/playing of an item. Items that are queued
for viewing/playing are only played when the user selects to present the media. A
Media Presenter tool is described later in this Section. Preferably, a button appears
in the control region 2016 to initiate presentation. Pressing this button involves
the current presentation tool which is a plug-in tool of the user's preference. It
should be clear that many such plug-in tools could be used. If a user was only interested
in images then only an image plug-in tool would be required. If a user was browsing
a range of content then a more sophisticated plug-in tool would be required. This
tool would need to be able invoke more specific tools for the playing/viewing of different
type of resources.
[0339] Preferably, items that have been selected are differentiated from unselected items
by highlighting the node content ( eg. displaying a node content's text in bold or
highlighting the frame of an image or visual icon). Selection of an item that contains
other items automatically selects the contained items.
[0340] TOC items can also be selected for context. Preferably, context selection is achieved
by right clicking the node symbol. This action results in a coloured frame being displayed
around both node symbol and the node content. Any context can be removed simply by
right-clicking on the node symbol (ie. right-clicking on the node symbol acts as a
toggle for select for context, just as left click on the node symbol acts as a toggle
for expand/collapse. Right clicking of the node content of an item can be used to
display properties of the corresponding item. Preferably, these properties contain
the index descriptors that pertain to that node item.
[0341] It should be clear to those skilled in the art that the browsing functions of the
TOC axis can be implemented in many different ways without departing from the spirit
and scope of the invention.
[0342] Preferably each axis of the Media Browser System can be scrolled. This means that
a section of the TOC can be retained in an expanded form and a further section scrolled
into view. The properties can be displayed in a small panel (like a callout) adjacent
to the node content.
[0343] Initially, the Index panel 2004 displays all index items associated with all the
table of contents items. In the present example, it can be seen that the item "Images
- Birthdays" 2008 of the Table of Contents has been currently selected for context
by the user. The Media Browser System 2000 then displays in the index panel 2004 a
list of indices determined by the description schemes that correspond to the currently
selected item of the Table of Contents (eg. in this case birthday images).
[0344] The Media Browser System also allows the user to further describe or annotate TOC
items. Annotation can be achieved by allowing the user to drag a displayed index item
onto displayed TOC items. An annotation of this form is only allowed if the dragged
index item is a valid descriptor for the corresponding TOC descriptor. For example,
a user would be allowed to drag a "People" index item onto a particular birthday image
if the corresponding "People" descriptor was a valid descriptor for the image descriptor.
The "People" descriptor is an example of a descriptor not having a representative
value, ie. it acts like a boolean indicator of the presence of a person in, in this
case, an image. Many index descriptors require representative values to be specified
as part of the annotation process. In these cases, as the required index item is dragged
onto the TOC item, if the corresponding descriptor is allowed for that TOC item, a
field of edit box is displayed for the user to enter the required representative value.
Preferably, the Media Browser System ensures that the entered representative value
is in the required form for the descriptor eg. dates may be specified to conform to
a particular ISO standard. Datatyping of representative values is discussed in Section
2.
[0345] Index descriptors that have been added to TOC items can be viewed by selecting to
view the properties of the TOC items. Preferably, properties of TOC items can be displayed
by right clicking the node content.
[0346] Preferably, all descriptors are viewed as being annotable. In the event a description's
origin is a remote database which is not available for update, the annotations are
stored locally as a copy of the updated description having a link to the remote description.
The link for the relevant TOC item is updated to point to the updated local copy of
the description. In a subsequent browsing session, the local copy of the description
is read and the description which is used by the browser is constructed by obtaining
the remote description and then modifying this description according to the local
copy. This method ensures that changes in the remote description are available to
the user ( ie. the local copy does not simply overwrite the original description).
An alternative way of achieving this is to only store locally annotations in a partial
description form. The form of these annotations could be defined by a special description
scheme.
[0347] Another variation of the annotation procedure would be to allow read-only descriptors.
For example, the core description element (as defined in Section 2) could be amended
to include a read-only attribute. If a description was classified as a read-only item
then a user would not be permitted to annotate TOC items corresponding to that description.
[0348] Preferably, the index panel 2004 contains an input box 2014 associated with each
index item for user entry of a query. In this way, a user may for example enter a
date query ( eg. July 1999) in the input box associated with date index. The Media
Browser will then highlight in the TOC any TOC items, that satisfy the query (ie.
have a date value of July 1999) and are contained in the currently selected context
of the TOC (ie. birthday images).
[0349] Preferably, the index panel 2004 also contains a input box 2010 for a user entry
of a free query. This input box 2010 is used as the input interface for a searching
engine across all description schemes. Preferably, the free query is entered as natural
language then subsequent processed into a structured query which uses index descripors
that correspond to the TOC context.
[0350] Alternatively, searching functionality can be provided by a plug-in tool that uses
the Media presentation pane 2006 to help the user construct a query using the index
panel 2004. This plug-in tool can be invoked by a user pressing a search button that
can be located in the control region 2016 at the bottom of the screen. The search
tool can allow a user to construct a query by dragging index items (which correspond
to index descriptors) from the index panel 2004 to the Media presentation pane 2006.
The plug-in tool can also allow a user to combine various descriptors using the logical
connectors typically used with search engines (eg. AND, OR, NOT etc), and allow a
user to formulate a free text query. Clearly any free text queries, whether entered
using the search plug-in tool or the input box 2010 would need to formulated in terms
of descriptor components. Inferencing techniques (as employed in some expert systems)
can be used for this purpose. The separate search plug-in tool could also optionally
display the results of the search in the Media presentation pane 2006 and allow the
user to select and play particular items returned by the search.
[0351] Other plug-in tools can provide additional functions to be applied to selected content
Each of these tools could be invoked in the manner described above for the search
tool. Alternatively, these tools could be invoked by a pull down menu option. These
additional functions could include emailing selected items to selected people (using,
for example, addresses from an address book of a commonly used email tool), or generating
an automatic presentation based on the selected content. The latter example could
use stylised templates that make presentation decisions based on the descriptor components
of selected resources.
[0352] The foregoing description of the Media Browser System assumes that descriptors are
classified according to their axis of access either by attributes which are part of
the description schemes or by using a set of rules for adding the attributes to the
description schemes. In the latter case the rules may be associated only with the
Media Browser application or can be more widely used in, for example, other applications.
[0353] In the event that the classifications cannot be achieved with one of the foregoing
methods, axes of access classifications for individual descriptors can be inferred
by the Media Browser System. This inferred classification can use information about
the base elements defined using the DDF. For example, a descriptor could be classified
as a TOC descriptor if it is directly associated with either a resource or a section
of the resource. If descriptions are generated according to the DDF then any descriptor
which is a specialisation of a description element will have an associated resource
through its definition (see Section 3.1.2.2) and any descriptor that contains a linking
element to a section of a resource (see Section 3.1.4) will have an associated resource
through the target of it link. These descriptors could be inferred to be TOC descriptors.
All remaining descriptors could be treated as index descriptors. Although this method
of classifying descriptors might not be ideal (eg., all non-TOC descriptors might
not appear to be sensible index descriptors), it does enable the Media Browser System
to present descriptions not having sufficient presentation rules.
1. A method of utilising electronically-accessible resources using descriptions of said
resources, wherein said descriptions of said resources have descriptor components,
said descriptor components having attributes representative of at least two axes of
access to the resources and wherein said descriptions have links to corresponding
said electronically-accessible resources, said method comprising the steps of:
reading said descriptions;
displaying items, wherein each item is associated with a corresponding said descriptor
component of a said read description that has at least one said attribute; and
browsing said descriptions of the resources and their corresponding electronically-accessible
resources via said links using said displayed items.
2. A method as claimed in claim 1, wherein each said read description is represented
by a tree of descriptor components, and one or more of said descriptor components
have descriptor components as descendents.
3. A method as claimed in claim 1, wherein one of said axes of access is a table-of-contents
classification.
4. A method as claimed in claim 1, wherein one of said axes of access is an index classification.
5. A method as claimed in claim 1, wherein the descriptions of the resources have been
generated using a description scheme as a template, and the description scheme uses
a declarative description definition language which contains definitions for descriptor
components of the said descriptions of the resources.
6. A method as claimed in claim 5, wherein said attributes of the descriptor components
are defined in the description scheme.
7. A method as claimed in claim 5, wherein the said attributes of the descriptor components
are a persistent item of the description scheme.
8. A method as claimed in claim 5, wherein the said attributes of the descriptor components
are instantiated by an application when required.
9. A method as claimed in claim 8, wherein the said attributes of the descriptor components
are instantiated using a rule that is associated with the description scheme.
10. A method as claimed in claim 1, wherein the resource is an item of digital content,
11. A method as claimed in claim 1, wherein the resource is an electronic document or
resource available over the World Wide Web.
12. A method as claimed in claim 1, wherein the resource is an electronic device.
13. A method as claimed in claim 1, wherein the description of the resource contains links
to identified sections of the resource.
14. A method as claimed in claim 1, wherein said axes of access are determined by rules
operating on the description.
15. A method as claimed in claim 1, wherein said axes of access are determined during
the generation of the description of the resource.
16. A method as claimed in claim 1, wherein said attributes of said descriptor components
representative of said at least two axes of access are inferred from the content of
the description.
17. A method as claimed in claim 16, wherein said attribute of a said descriptor component
is inferred to be a table of content descriptor if the said descriptor component contains
a reference to a resource or a section of a resource.
18. A method as claimed in claim 17, wherein said attribute of a said descriptor component
is inferred to be an index descriptor if the said descriptor component is not inferred
to be a table of contents descriptor.
19. A method of utlising electronically-accessible resources using descriptions of said
resources, wherein said descriptions of said resources have descriptor components,
said descriptor components having attributes representative of at least two axes of
access to the resources and wherein said descriptions have links to corresponding
said electronically-accessible resources, said method comprising the steps of:
reading said descriptions;
displaying items, wherein each item is associated with a corresponding said descriptor
component of a said read description that has at least one said attribute;
specifying a query in terms of index descriptors;
searching said descriptions of the resources using said query; and
locating said corresponding electronically-accessible resources using said links associated
with said displayed items.
20. A method as claimed in claim 19, wherein each said read description is represented
by a tree of descriptor components, and one or more of said descriptor components
have descriptor components as descendents.
21. A method as claimed in claim 19, wherein said method further comprises the step of:
playing resources corresponding to said located descriptions of resources.
22. A method as claimed in claim 19, wherein said attributes of said descriptor components
representative of said at least two axes of access are inferred from the content of
the description.
23. A method as claimed in claim 22, wherein said attribute of a said descriptor component
is inferred to be a table of content descriptor if the said descriptor component contains
a reference to a resource or a section of a resource.
24. A method as claimed in claim 23, wherein said attribute of a said descriptor component
is inferred to be an index descriptor if the said descriptor component is not inferred
to be a table of contents descriptor.
25. A method of utilising electronically-accessible resources using descriptions of said
resources, wherein the descriptions of said resources have descriptor components,
each said descriptor component comprises the association of a feature of a said resource
with a representative value for that feature, and one or more of said descriptor components
including a table of contents attribute and one or more of said descriptor components
including an index attribute, and wherein said descriptions have links to corresponding
said electronically- accessible resources, said method comprising the steps of:
reading said descriptions;
displaying a table of contents containing table of contents items, wherein each table
of contents item is associated with a corresponding said descriptor component that
has a table of contents attribute;
selecting one said displayed table of contents item;
displaying an index containing index items, wherein each said displayed index item
is associated with a corresponding said descriptor component that has an index attribute
and that is associated with the said selected table of contents item;
selecting one or more index items in the displayed index;
specifying a said representative value or values for the one or more said selected
index items;
searching said descriptions of the resources for said one, or more selected index
items and their corresponding said specified representative value or values; and
locating one or more said descriptions of the resources corresponding to said one
or more selected index items and their corresponding said specified representative
value or values.
26. A method as claimed in claim 25, wherein each said read description is represented
by a tree of descriptor components, and one or more of said descriptor components
have descriptor components as descendents.
27. A method as claimed in claim 25, wherein said method further comprises the step of:
playing resources corresponding to said located descriptions of resources.
28. A method as claimed in claim 25, wherein said step of selecting one said table of
contents item is optional and if not performed said step of displaying an index displays
nil said index items associated with all said table of contents items.
29. A method as claimed in claim 25, wherein said selecting step of index items comprises
selecting logical combinations of said displayed index items and their said representative
values.
30. A method as claimed in claim 25, wherein said attribute of a said descriptor component
is inferred to be a table of content descriptor if the said descriptor component contains
a reference to a resource or a section of a resource.
31. A method as claimed in claim 30, wherein said attribute of a said descriptor component
is inferred to be an index descriptor if the said descriptor component is not inferred
to be a table of contents descriptor.
32. A method of utilising an electronically-accessible resource using a description of
said resource, wherein the description of said resource has descriptor components,
each said descriptor component comprises the association of a feature of said resource
with a representative value for that feature, and one or more of said descriptor components
including a table of contents attribute and one or more of said descriptor components
including an index attribute, said method comprising the steps of:
reading said descriptions;
displaying a table of contents containing table of contents items, wherein each table
of contents item is associated with a corresponding said descriptor component that
has a table of contents attribute;
selecting one said displayed table of contents item for the annotation;
displaying an index containing index items, wherein each said displayed index item
is associated with a corresponding said descriptor component that has an index attribute
and that is associated with the said selected table of contents item;
selecting one said displayed index item;
associating said selected displayed index item with said selected table of contents
item;
choosing a said representative value for the selected index item; and
associating said chosen representative value with said feature which corresponds to
said selected index item, wherein said chosen representative value and its corresponding
feature provide an annotation of the resource.
33. A method as claimed in claim 32, wherein each said read description is represented
by a tree of descriptor components, and one or more of said descriptor components
have descriptor components as descendents.
34. A method as claimed in claim 32, wherein said step of associating said selected display
index item is allowed only if the corresponding descriptor of said selected display
index item is a valid descriptor for the table of contents item selected for annotation.
35. A method as claimed in claim 32, wherein said step of choosing a said representative
value is predetermined.
36. Apparatus for utilising electronically-accessible resources using descriptions of
said resources, wherein said descriptions of said resources have descriptor components,
said descriptor components having attributes representative of at least two axes of
access to the resources and wherein said descriptions have links to corresponding
said electronically-accessible resources, said apparatus comprising:
means for reading said descriptions;
means for displaying items, wherein each item is associated with a corresponding said
descriptor component of a said read description that has at least one said attribute;
and
means for browsing said descriptions of the resources and their corresponding electronically-accessible
resources via said links using said displayed items.
37. Apparatus as claimed as claimed in claim 36, wherein said means for reading said descriptions
represents each description by a tree of descriptor components, and one or more of
said descriptor components have descriptor components as descendents.
38. Apparatus as claimed in claim 36, wherein one of said axes of access is a table-of-contents
classification.
39. Apparatus as claimed in claim 36, wherein one of said axes of access is an index classification.
40. Apparatus as claimed in claim 36, wherein the descriptions of the resources have been
provided using a description scheme as a template, and the description scheme uses
a declarative description definition language which contains definitions for descriptor
components of the said descriptions of the resources.
41. Apparatus as claimed in claim 40, wherein said attributes of the descriptor components
are defined in the description scheme.
42. Apparatus as claimed in claim 40, wherein the said attributes of the descriptor components
are a persistent item of the description scheme.
43. Apparatus as claimed in claim 40, wherein the said attributes of the descriptor components
are instantiated by an application when required.
44. Apparatus as claimed in claim 43, wherein the said attributes of the descriptor components
are instantiated using a rule that is associated with the description scheme.
45. Apparatus as claimed in claim 36, wherein the resource is an item of digital content.
46. Apparatus as claimed in claim 36, wherein the resource is an electronic document or
resource available over the World Wide Web.
47. Apparatus as claimed in claim 36, wherein the resource is an electronic device.
48. Apparatus as claimed in claim 36, wherein the description of the resource contains
links to identified sections of the resource.
49. Apparatus as claimed in claim 36, wherein said axes of access are determined by rules
operating on the description.
50. Apparatus as claimed in claim 36, wherein said axes of access are determined during
the generation of the description of the resource.
51. Apparatus as claimed in claim 36, wherein said attributes of said descriptor components
representative of said at least two axes of access are inferred from the content of
the description.
52. Apparatus as claimed in claim 51, wherein said attribute of a said descriptor component
is inferred to be a table of content descriptor if the said descriptor component contains
a reference to a resources or a section of a resource.
53. Apparatus as claimed in claim 52, wherein said attribute of a said descriptor component
is inferred to be an index descriptor if the said descriptor component is not inferred
to be a table of contents descriptor.
54. Apparatus for utilising electronically-accessible resources using descriptions of
said resources, wherein said descriptions of said resources have descriptor components,
said descriptor components having attributes representative of at least two axes of
access to the resources and wherein said descriptions have links to corresponding
said electronically-accessible resources, said apparatus comprising:
means for reading said descriptions;
means for displaying items, wherein each item is associated with a corresponding said
descriptor component of a said read description that has at least one said attribute;
means for specifying a query in terms of index descriptors:
means for searching said descriptions of the resources using said query; and
means for locating said corresponding electronically-accessible resources using said
links associated with said displayed items.
55. Apparatus as claimed in claim 54, wherein said read means represents each said description
by a tree of descriptor components, and one or more of said descriptor components
have descriptor components as descendents.
56. Apparatus as claimed in claim 54, wherein said apparatus further comprises: means
for playing resources corresponding to said located descriptions of resources.
57. Apparatus as claimed in claim 54, wherein said attributes of said descriptor components
representative of said at least two axes of access are inferred from the content of
the description.
58. Apparatus as claimed in claim 57, wherein said attribute of a said descriptor component
is inferred to be a table of content descriptor if the said descriptor component contains
a reference to a resources or a section of a resource.
59. Apparatus as claimed in claim 58, wherein said attribute of a said descriptor component
is inferred to be an index descriptor if the said descriptor component is not inferred
to be a table of contents descriptor.
60. Apparatus for utilising electronically-accessible resources using descriptions of
said resources, wherein the descriptions of said resources have descriptor components,
each said descriptor component comprises the association of a feature of a said resource
with a representative value for that feature, and one or more of said descriptor components
including a table of contents attribute and one or more of said descriptor components
including an index attribute, and wherein said descriptions have links to corresponding
said electronically- accessible resources, said apparatus comprising:
means for reading said descriptions;
means for displaying a table of contents containing table of contents items, wherein
each table of contents item is associated with a corresponding said descriptor component
that has a table of contents attribute;
means for selecting one said displayed table of contents item;
means for displaying an index containing index items, wherein each said displayed
index item is associated with a corresponding said descriptor component that has an
index attribute and that is associated with the said selected table of contents item;
means for selecting one or more index items in the displayed index;
means for specifying a said representative value or values for the one or more said
selected index items;
means for searching said descriptions of the resources for said one or more selected
index items and their corresponding said specified representative value or values;
and
means for locating one or more said descriptions of the resources corresponding to
said one or more selected index items and their corresponding said specified representative
value or values.
61. A method as claimed in claim 60, wherein said read means represents each said description
by a tree of descriptor components, and one or more of said descriptor components
have descriptor components as descendents.
62. Apparatus as claimed in claim 60, wherein said apparatus further comprises: means
for playing resources corresponding to said located descriptions of resources.
63. Apparatus as claimed in claim 60, wherein operation of said means for selecting one
said table of contents item is optional and if not performed said means for displaying
an index displays all said index items associated with all said table of contents
items.
64. Apparatus as claimed in claim 60, wherein said means for selecting said representative
value or values comprise means for selecting logical combinations of said displayed
index items and their said representative values.
65. Apparatus as claimed in claim 64, wherein said attribute of a said descriptor component
is inferred to be a table of content descriptor if the said descriptor component contains
a reference to a resources or a section of a resource.
66. Apparatus as claimed in claim 65, wherein said attribute of a said descriptor component
is inferred to be an index descriptor if the said descriptor component is not inferred
to be a table of contents descriptor.
67. Apparatus for utilising an electronically-accessible resource using a description
of said resource, wherein the description of said resource has descriptor components,
each said descriptor component comprises the association of a feature of said resource
with a representative value for that feature, and one or more of said descriptor components
including a table of contents attribute and one or more of said descriptor components
including an index attribute, said apparatus comprising:
means for reading said descriptions;
means for displaying a table of contents containing table contents items, wherein
each table of contents item is associated with a corresponding said descriptor component
that has a table of contents attribute;
means for selecting one said displayed table of contents item for the annotation;
means for displaying an index containing index items, wherein each said displayed
index item is associated with a corresponding said descriptor component that has an
index attribute and that is associated with the said selected table of contents item;
means for selecting one said displayed index item;
means for associating said selected displayed index item with said selected table
of contents item;
means for choosing a said representative value for the selected index item; and
means for associating said chosen representative value with said feature which corresponds
to said selected index item, wherein said chosen representative value and its corresponding
feature provide an annotation of the resource.
68. Apparatus as claimed in claim 67, wherein said read means represents each said description
by a tree of descriptor components, and one or more of said descriptor components
have descriptor components as descendents.
69. Apparatus as claimed in claim 67, wherein operation of said means for associating
said selected display index item is allowed only if the corresponding descriptor of
said selected display index item is a valid descriptor for the table of contents item
selected for annotation.
70. Apparatus as claimed in claim 67, wherein operation of said means for selecting one
said table of contents item is optional and if not performed said means for displaying
an index displays all said index items associated with all said table of contents
items.
71. A computer readable medium comprising a computer program for utlising electronically-accessible
resources using descriptions of said resources, wherein said descriptions of said
resources have descriptor components, said descriptor components having attributes
representative of at least two axes of access to the resources and wherein said descriptions
have links to corresponding said electronically- accessible resources, said computer
program comprising:
code for reading said descriptions;
code for displaying items, wherein each item is associated with a corresponding said
descriptor component of a said read description that has at least one said attribute;
and
code for browsing said descriptions of the resources and their corresponding electronically-accessible
resources via said links using said displayed items.
72. A computer readable medium comprising a computer program for utilising electronically-accessible
resources using descriptions of said resources, wherein said descriptions of said
resources have descriptor components, said descriptor components having attributes
representative of at least two axes of access to the resources and wherein said descriptions
have links to corresponding said electronically- accessible resources, said computer
program comprising:
code for reading said descriptions;
code for displaying items, wherein each item is associated with a corresponding said
descriptor component of a said read description that has at least one said attribute;
code for specifying a query in terms of index descriptor;
code for searching said descriptions of the resources using said query; and
code for locating said corresponding electronically-accessible resources using said
links associated with said displayed items.
73. A computer readable medium comprising a computer program for utilising electronically-accessible
resources using descriptions of said resources, wherein the descriptions of said resources
have descriptor components, each said descriptor component comprises the association
of a feature of a said resource with a representative value for that feature, and
one or more of said descriptor components including a table of contents attribute
and one or more of said descriptor components including an index attribute, and wherein
said descriptions have links to corresponding said electronically-accessible resources,
said computer program comprising:
code for reading said descriptions;
code for displaying a table of contents containing table of contents items, wherein
each table of contents item is associated with a corresponding said descriptor component
that has a table of contents attribute;
code for selecting one said displayed table of contents item;
code for displaying an index containing index items, wherein each said displayed index
item is associated with a corresponding said descriptor component that has an index
attribute and that is associated with the said selected table of contents item;
code for selecting one or more index items in the displayed index;
code for specifying a said representative value or values for the one or more said
selected index items;
code for searching said descriptions of the resources for said one or more selected
index items and their corresponding said specified representative value or values;
and
code for locating one or more said descriptions of the resources corresponding to
said one or more selected index items and their corresponding said specified representative
value or values.
74. A computer readable medium comprising a computer program for utilising an electronically-accessible
resource using a description of said resource, wherein the description of said resource
has descriptor components, each said descriptor component comprises the association
of a feature of said resource with a representative value for that feature, and one
or more of said descriptor components including a table of contents attribute and
one or more of said descriptor components including an index attribute, said computer
program comprising:
code for reading said descriptions;
code for displaying a table of contents containing table of contents items, wherein
each table of contents item is associated with a corresponding said descriptor component
that has a table of contents attribute;
code for selecting one said displayed table of contents item for the annotation;
code for displaying an index containing index items, wherein each said displayed index
item is associated with a corresponding said descriptor component that has an index
attribute and that is associated with the said selected table of contents item;
code for selecting one said displayed index item;
code for associating said selected displayed index item with said selected table of
contents item;
code for choosing a said representative value for the selected index item; and
code for associating said chosen representative value with said feature which corresponds
to said selected index item, wherein said chosen representative value and its corresponding
feature provide an annotation of the resource.
75. A method of selecting one or more descriptions or one or more descriptor components
from a set of descriptions, wherein said descriptions comprise one or more said descriptor
components, and each said description of said set of descriptions is associated with
a corresponding electronically accessible resource, said method comprising the steps
of:
specifying a desired selection of descriptor components;
generating a selection rule based on said specified descriptor components, wherein
said selection rule having a predetermined pattern and action component, wherein the
said predetermined pattern represents a specified pattern of descriptor components
and the said action specifies the action to be performed when a said descriptor component
in the descriptions of the set of descriptions matches the predetermined pattern;
reading said descriptions of the resources;
locating patterns of descriptor components in descriptions of said set of descriptions
in order to select descriptor components or descriptions in said set of descriptions
having said descriptor components which match the predetermined pattern; and
performing said specified action.
76. The method as claimed in claim 75, wherein each said read description is represented
by a tree of descriptor components, and one or more said descriptor components have
descriptor components as descendents.
77. The method as claimed in claim 76, wherein said predetermined pattern is represented
using the context of said tree of descriptor components.
78. The method as claimed in claim 77, wherein the said action component of the selection
rule involves setting the value of a predetermined descriptor attribute in order to
indicate which descriptor components have been selected to an application.
79. The method as claimed in claim 76, wherein the said predetermined descriptor attribute
is also set for each of the ancestors of a descriptor component which matches the
said predetermined pattern.
80. The method as claimed in claim 76, wherein the said predetermined descriptor attribute
is also set for the root descriptor of the tree containing a descriptor which matches
the said predetermined pattern.
81. The method as claimed in claim 80, wherein the setting of the predetermined descriptor
attribute for the root descriptor of the tree corresponds to the selection of the
description.
82. The method as claimed in claim 79, wherein the said pattern component of the said
selection rule is automatically set to the current structural context set by a browsing
application.
83. Apparatus for selecting one or more descriptions or one or more descriptor components
from a set of descriptions, wherein said descriptions comprise one or more said descriptor
components, and each said description of said set of descriptions is associated with
a corresponding electronically accessible resource, said apparatus comprising:
means for specifying a desired selection of descriptor components;
means for generating a selection rule based on said specified descriptor components,
wherein said selection rule having a predetermined pattern and action component wherein
the said predetermined pattern represents a specified pattern of descriptor components
and the said action specifies the action to be performed when a said descriptor component
in the descriptions of the set of descriptions matches the predetermined pattern;
means for reading said descriptions of the resources;
means for locating patterns of descriptor components in descriptions of said set of
descriptions in order to select descriptor components or descriptions in said set
of descriptions having said descriptor components which match the predetermined pattern;
and
means for performing said specified action.
84. A computer readable medium comprising a computer program for selecting one or more
descriptions or one or more descriptor components from a set of descriptions, wherein
said descriptions comprise one or more said descriptor components, and each said description
of said set of descriptions is associated with a corresponding electronically accessible
resource, said computer program comprising:
code for specifying a desired selection of descriptor components;
code for generating a selection rule based on said specified descriptor components,
wherein said selection rule having a predetermined pattern and action component, wherein
the said predetermined pattern represents a specified pattern of descriptor components
and the said action specifies the action to be performed when a said descriptor component
in the descriptions of the set of descriptions matches the predetermined pattern;
code for reading said descriptions of the resources;
code for locating patterns of descriptor components in descriptions of said set of
descriptions in order to select descriptor components or descriptions in said set
of descriptions having said descriptor components which match the predetermined pattern;
and
code for performing said specified action.
85. A method of generating on an output device a presentation based on a predetermined
selection of resources, said method comprising the steps of:
reading a description scheme for said presentation, wherein the description scheme
for said presentation uses a declarative description definition language which contains
definitions for descriptor components of the description scheme;
generating a description of the said presentation using said description scheme and
said predetermined selection of said resources; and
generating on said output device the said presentation based on the said description
of the said presentation and the predetermined selected resources.
86. The method as claimed in claim 85, wherein said resources are digital video resources
and said presentation is a video presentation.
87. The method as claimed in claim 86, wherein said output device is a display device.
88. The method as claimed in claim 85, wherein said description scheme has an associated
reference to procedural code for the instantiation of a descriptor in the description
of the presentation.
89. The method as claimed in claim 86, wherein the said description of the video presentation
can specify sections of different individual digital video resources to be used to
render the video presentation.
90. The method as claimed in claim 85, wherein the method comprises associating with the
said description scheme a set of presentation rules.
91. The method as claimed in claim 90, wherein the presentation rules specify the type
of transitions that are to be rendered between sections of the presentations.
92. The method as claimed in claim 90, wherein the presentation rules specify whether
a title is rendered for the presentation.
93. The method as claimed in claim 90, wherein the presentation rules specify the spatial
placement, colour, font and/or size of a tide to be rendered for the presentation.
94. The method as claimed in claim 86, wherein the method comprises associating with the
said description scheme a set of presentation rules and the presentation rules specify
the speed at which components are played in the video presentation.
95. The method as claimed in claim 85, wherein the method further comprises associating
with the said description scheme a set of presentation rules which specify characteristics
of the style of the presentation for said description generated using the said description
scheme.
96. The method as claimed in claim 95, associating with the said description a further
set of presentation rules which specify characteristics of the style of the presentation
to be generated from the said description.
97. The method as claimed in claim 94, wherein the presentation rules specify that a particular
component of a presentation is to be played at the original recorded speed, a slower
speed or a faster speed.
98. The method as claimed in claim 85, wherein said resources are digital image resources.
99. The method as claimed in claim 85, wherein said presentation is a printed presentation.
100. The method as claimed in claim 85, wherein said output device is a printer device.
101. The method as claimed in claim 99, wherein the method comprises associating with the
said description scheme a set of presentation rules and said presentation rules specify
the spatial layout of the printed presentation.
102. The method as claimed in claim 99, wherein the method comprises associating with the
said description scheme a set of presentation rules and said presentation rules specify
colour information for the printed presentation.
103. The method as claimed in claim 98, wherein the said digital image resources contains
image frames from digital video resources stored on a DVD.
104. The method as claimed in claim 85, wherein the step of reading a description scheme
and the step of generating a description are performed on a source device and said
step of generating said presentation is performed on said output device and said method
further comprises the step of:
communicating the said description from the source to the output device via a wireless
connection.
105. The method as claimed in claim 104, wherein the resources are digital video resources
which are stored and accessed from a processing server, which is separate from and
has a wireless connection to the said source device, and a connection to the said
output device.
106. The method as claimed in claim 105, wherein the said processing server renders the
presentation for viewing from the description of the presentation and communicates
the rendered presentation to the said output device.
107. The method as claimed in claim 105, wherein the said processing server communicates
both the description of the presentation and the associated digital video resources
to the said output device which subsequently renders the presentation for viewing.
108. The method as claimed in claim 104, wherein the resources are digital video resources
which are stored and accessed from the said source device and communicated with the
said description of the presentation to the said output device, which has digital
video display capability.
109. The method as claimed in claim 108, wherein a digital video resource associated with
the description is communicated via the wireless connection in encoded format.
110. The method as claimed in claim 108, wherein a digital video resource associated with
the description is communicated via the wireless connection in compressed format.
111. A method of generating on an output device a presentation based on a predetermined
selection of resources, said method comprising the steps of:
reading a description scheme for said presentation, wherein said description scheme
contains definitions for descriptor components of the description scheme, and each
said descriptor component comprises the association of a presentation attribute with
a representative value for that attribute;
generating a description of the said presentation using said description scheme and
said predetermined selection of resources; and
generating on said output device the said presentation based on the said generated
description of the said presentation, the predetermined selected resources, and a
set of presentation rules, which rules specify characteristics of the style of said
generated presentation, wherein said set of presentation rules are associated with
said description scheme.
112. The method as claimed in claim 111, wherein said description scheme uses a declaration
description definition language.
113. Apparatus for generating on an output device a presentation based on a predetermined
selection of resources, said apparatus comprising:
means for reading a description scheme for said presentation, wherein the description
scheme for said presentation uses a declarative description definition language which
contains definitions for descriptor components of the description scheme;
means for generating a description of the said presentation using said description
scheme and said predetermined selection of said resources; and
means for generating on said output device the said presentation based on the said
description of the said presentation and the predetermined selected resources.
114. Apparatus for generating on an output device a presentation based on a predetermined
selection of resources, said apparatus comprising:
means for reading a description scheme for said presentation, wherein said description
scheme contains definitions for descriptor components of the description scheme, and
each said descriptor component comprises the association of a presentation attribute
with a representative value for that attribute;
means for generating a description of the said presentation using said description
scheme and said predetermined selection of resources; and
means for generating on said output device the said presentation based on the said
generated description of the said presentation, the predetermined selected resources,
and a set of presentation rules, which rules specify characteristics of the style
of said generated presentation, wherein said set of presentation rules are associated
with said description scheme.
115. A computer readable medium comprising a computer program for generating on an output
device a presentation based on a predetermined selection of resources, said computer
program comprising:
code for reading a description scheme for said presentation, wherein the description
scheme for said presentation uses a declarative description definition language which
contains definitions for descriptor components of the description scheme;
code for generating a description of the said presentation using said description
scheme and said predetermined selection of said resources; and
code for generating on said output device the said presentation based on the said
description of the said presentation and the predetermined selected resources.
116. A computer readable medium comprising a computer program for generating on an output
device a presentation based on a predetermined selection of resources, said computer
program comprising:
code for reading a description scheme for said presentation, wherein said description
scheme contains definitions for descriptor components of the description scheme, and
each said descriptor component comprises the association of a presentation attribute
with a representative value for that attribute;
code for generating a description of the said presentation using said description
scheme and said predetermined selection of resources; and
code for generating on said output device the said presentation based on the said
generated description of the said presentation, the predetermined selected resources,
and a set of presentation rules, which rules specify characteristics of the style
of said generated presentation, wherein said set of presentation rules are associated
with said description scheme.